diff --git a/.github/actions/java-test/action.yaml b/.github/actions/java-test/action.yaml
index c0ff974aa3..634c42a640 100644
--- a/.github/actions/java-test/action.yaml
+++ b/.github/actions/java-test/action.yaml
@@ -26,6 +26,10 @@ inputs:
     description: 'Maven options passed to the mvn command'
     required: false
     default: ''
+  scan_impl:
+    description: 'The default Parquet scan implementation'
+    required: false
+    default: 'native_comet'
   upload-test-reports:
     description: 'Whether to upload test results including coverage to GitHub'
     required: false
@@ -58,11 +62,15 @@ runs:
     - name: Run all tests
       shell: bash
       if: ${{ inputs.suites == '' }}
+      env:
+        COMET_PARQUET_SCAN_IMPL: ${{ inputs.scan_impl }}
       run: |
         MAVEN_OPTS="-XX:+UnlockDiagnosticVMOptions -XX:+ShowMessageBoxOnError -XX:+HeapDumpOnOutOfMemoryError -XX:ErrorFile=./hs_err_pid%p.log" SPARK_HOME=`pwd` ./mvnw -B clean install ${{ inputs.maven_opts }}
     - name: Run specified tests
       shell: bash
       if: ${{ inputs.suites != '' }}
+      env:
+        COMET_PARQUET_SCAN_IMPL: ${{ inputs.scan_impl }}
       run: |
         MAVEN_SUITES="$(echo "${{ inputs.suites }}" | paste -sd, -)"
         echo "Running with MAVEN_SUITES=$MAVEN_SUITES"
diff --git a/.github/workflows/pr_build.yml b/.github/workflows/pr_build.yml
deleted file mode 100644
index 308dd2d68c..0000000000
--- a/.github/workflows/pr_build.yml
+++ /dev/null
@@ -1,317 +0,0 @@
-# Licensed to the Apache Software Foundation (ASF) under one
-# or more contributor license agreements.  See the NOTICE file
-# distributed with this work for additional information
-# regarding copyright ownership.  The ASF licenses this file
-# to you under the Apache License, Version 2.0 (the
-# "License"); you may not use this file except in compliance
-# with the License.  You may obtain a copy of the License at
-#
-#   http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing,
-# software distributed under the License is distributed on an
-# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
-# KIND, either express or implied.  See the License for the
-# specific language governing permissions and limitations
-# under the License.
-
-name: PR Build
-
-concurrency:
-  group: ${{ github.repository }}-${{ github.head_ref || github.sha }}-${{ github.workflow }}
-  cancel-in-progress: true
-
-on:
-  push:
-    paths-ignore:
-      - "doc/**"
-      - "docs/**"
-      - "**.md"
-  pull_request:
-    paths-ignore:
-      - "doc/**"
-      - "docs/**"
-      - "**.md"
-  # manual trigger
-  # https://docs.github.com/en/actions/managing-workflow-runs/manually-running-a-workflow
-  workflow_dispatch:
-
-env:
-  RUST_VERSION: stable
-
-jobs:
-
-  # run Comet test with full matrix of Java and Scala versions for the latest supported 3.5.x release
-  linux-test:
-    strategy:
-      matrix:
-        os: [ubuntu-latest]
-        java_version: [11, 17]
-        test-target: [rust, java]
-        spark-version: ['3.5']
-        scala-version: ['2.12', '2.13']
-        is_push_event:
-          - ${{ github.event_name == 'push' }}
-        exclude: # exclude java 11 for pull_request event
-          - java_version: 11
-            is_push_event: false
-      fail-fast: false
-    name: ${{ matrix.os }}/java ${{ matrix.java_version }}-spark-${{matrix.spark-version}}-scala-${{matrix.scala-version}}/${{ matrix.test-target }}
-    runs-on: ${{ matrix.os }}
-    container:
-      image: amd64/rust
-    steps:
-      - uses: actions/checkout@v4
-      - name: Setup Rust & Java toolchain
-        uses: ./.github/actions/setup-builder
-        with:
-          rust-version: ${{env.RUST_VERSION}}
-          jdk-version: ${{ matrix.java_version }}
-      - if: matrix.test-target == 'rust'
-        name: Rust test steps
-        uses: ./.github/actions/rust-test
-      - if: matrix.test-target == 'java'
-        name: Java test steps
-        uses: ./.github/actions/java-test
-        with:
-          maven_opts: -Pspark-${{ matrix.spark-version }},scala-${{ matrix.scala-version }}
-          # upload test reports only for java 17
-          upload-test-reports: ${{ matrix.java_version == '17' }}
-
-  # run Comet tests for older 3.5.x releases with one java and scala versions
-  linux-test-35-minor-versions:
-    strategy:
-      matrix:
-        os: [ubuntu-latest]
-        java_version: [17]
-        test-target: [java]
-        spark-version: ['3.5']
-        spark-patch-version: ['3.5.2', '3.5.3', '3.5.4']
-        scala-version: ['2.12']
-        is_push_event:
-          - ${{ github.event_name == 'push' }}
-      fail-fast: false
-    name: ${{ matrix.os }}/java ${{ matrix.java_version }}-spark-${{matrix.spark-patch-version}}-scala-${{matrix.scala-version}}/${{ matrix.test-target }}
-    runs-on: ${{ matrix.os }}
-    container:
-      image: amd64/rust
-    steps:
-      - uses: actions/checkout@v4
-      - name: Setup Rust & Java toolchain
-        uses: ./.github/actions/setup-builder
-        with:
-          rust-version: ${{env.RUST_VERSION}}
-          jdk-version: ${{ matrix.java_version }}
-      - if: matrix.test-target == 'rust'
-        name: Rust test steps
-        uses: ./.github/actions/rust-test
-      - if: matrix.test-target == 'java'
-        name: Java test steps
-        uses: ./.github/actions/java-test
-        with:
-          maven_opts: "-Pspark-${{ matrix.spark-version }},scala-${{ matrix.scala-version }} -Dspark.version=${{ matrix.spark-patch-version }}"
-          # upload test reports only for java 17
-          upload-test-reports: ${{ matrix.java_version == '17' }}
-
-  linux-test-native-datafusion-scan:
-    strategy:
-      matrix:
-        os: [ubuntu-latest]
-        scan_impl: ['native_datafusion', 'native_iceberg_compat']
-        java_version: [17]
-        test-target: [rust, java]
-        spark-version: ['3.5']
-        scala-version: ['2.12']
-        is_push_event:
-          - ${{ github.event_name == 'push' }}
-      fail-fast: false
-    name: ${{ matrix.os }}/java ${{ matrix.java_version }}-spark-${{matrix.spark-version}}-scala-${{matrix.scala-version}}/${{ matrix.test-target }}-${{ matrix.scan_impl }}
-    runs-on: ${{ matrix.os }}
-    env:
-      COMET_PARQUET_SCAN_IMPL: ${{ matrix.scan_impl }}
-    container:
-      image: amd64/rust
-    steps:
-      - uses: actions/checkout@v4
-      - name: Setup Rust & Java toolchain
-        uses: ./.github/actions/setup-builder
-        with:
-          rust-version: ${{env.RUST_VERSION}}
-          jdk-version: ${{ matrix.java_version }}
-      - if: matrix.test-target == 'rust'
-        name: Rust test steps
-        uses: ./.github/actions/rust-test
-      - if: matrix.test-target == 'java'
-        name: Java test steps
-        uses: ./.github/actions/java-test
-        with:
-          maven_opts: -Pspark-${{ matrix.spark-version }},scala-${{ matrix.scala-version }}
-          # upload test reports only for java 17
-          upload-test-reports: ${{ matrix.java_version == '17' }}
-
-  linux-test-with-old-spark:
-    strategy:
-      matrix:
-        os: [ubuntu-latest]
-        java_version: [11, 17]
-        test-target: [java]
-        spark-version: ['3.4']
-        scala-version: ['2.12', '2.13']
-      fail-fast: false
-    name: ${{ matrix.os }}/java ${{ matrix.java_version }}-spark-${{matrix.spark-version}}-scala-${{matrix.scala-version}}/${{ matrix.test-target }}
-    runs-on: ${{ matrix.os }}
-    container:
-      image: amd64/rust
-    steps:
-      - uses: actions/checkout@v4
-      - name: Setup Rust & Java toolchain
-        uses: ./.github/actions/setup-builder
-        with:
-          rust-version: ${{env.RUST_VERSION}}
-          jdk-version: ${{ matrix.java_version }}
-      - name: Java test steps
-        uses: ./.github/actions/java-test
-        with:
-          maven_opts: -Pspark-${{ matrix.spark-version }},scala-${{ matrix.scala-version }}
-
-  macos-test:
-    strategy:
-      matrix:
-        os: [macos-13]
-        java_version: [11, 17]
-        test-target: [rust, java]
-        spark-version: ['3.4', '3.5']
-        scala-version: ['2.12', '2.13']
-      fail-fast: false
-    if: github.event_name == 'push'
-    name: ${{ matrix.os }}/java ${{ matrix.java_version }}-spark-${{matrix.spark-version}}-scala-${{matrix.scala-version}}/${{ matrix.test-target }}
-    runs-on: ${{ matrix.os }}
-    steps:
-      - uses: actions/checkout@v4
-      - name: Setup Rust & Java toolchain
-        uses: ./.github/actions/setup-macos-builder
-        with:
-          rust-version: ${{env.RUST_VERSION}}
-          jdk-version: ${{ matrix.java_version }}
-      - if: matrix.test-target == 'rust'
-        name: Rust test steps
-        uses: ./.github/actions/rust-test
-      - if: matrix.test-target == 'java'
-        name: Java test steps
-        uses: ./.github/actions/java-test
-        with:
-          maven_opts: -Pspark-${{ matrix.spark-version }},scala-${{ matrix.scala-version }}
-
-  macos-aarch64-test:
-    strategy:
-      matrix:
-        java_version: [11, 17]
-        test-target: [rust, java]
-        spark-version: ['3.4', '3.5']
-        scala-version: ['2.12', '2.13']
-        is_push_event:
-          - ${{ github.event_name == 'push' }}
-        exclude: # exclude java 11 for pull_request event
-          - java_version: 11
-            is_push_event: false
-      fail-fast: false
-    name: macos-14(Silicon)/java ${{ matrix.java_version }}-spark-${{matrix.spark-version}}-scala-${{matrix.scala-version}}/${{ matrix.test-target }}
-    runs-on: macos-14
-    steps:
-      - uses: actions/checkout@v4
-      - name: Setup Rust & Java toolchain
-        uses: ./.github/actions/setup-macos-builder
-        with:
-          rust-version: ${{env.RUST_VERSION}}
-          jdk-version: ${{ matrix.java_version }}
-          jdk-architecture: aarch64
-          protoc-architecture: aarch_64
-      - if: matrix.test-target == 'rust'
-        name: Rust test steps
-        uses: ./.github/actions/rust-test
-      - if: matrix.test-target == 'java'
-        name: Java test steps
-        uses: ./.github/actions/java-test
-        with:
-          maven_opts: -Pspark-${{ matrix.spark-version }},scala-${{ matrix.scala-version }}
-
-  macos-test-with-spark4_0:
-    strategy:
-      matrix:
-        os: [macos-13]
-        java_version: [17]
-        test-target: [java]
-        spark-version: ['4.0']
-      fail-fast: false
-    if: github.event_name == 'push'
-    name: ${{ matrix.os }}/java ${{ matrix.java_version }}-spark-${{matrix.spark-version}}/${{ matrix.test-target }}
-    runs-on: ${{ matrix.os }}
-    steps:
-      - uses: actions/checkout@v4
-      - name: Setup Rust & Java toolchain
-        uses: ./.github/actions/setup-macos-builder
-        with:
-          rust-version: ${{env.RUST_VERSION}}
-          jdk-version: ${{ matrix.java_version }}
-      - name: Java test steps
-        uses: ./.github/actions/java-test
-        with:
-          maven_opts: -Pspark-${{ matrix.spark-version }}
-          upload-test-reports: true
-
-  macos-aarch64-test-with-spark4_0:
-    strategy:
-      matrix:
-        java_version: [17]
-        test-target: [java]
-        spark-version: ['4.0']
-        is_push_event:
-          - ${{ github.event_name == 'push' }}
-        exclude: # exclude java 11 for pull_request event
-          - java_version: 11
-            is_push_event: false
-      fail-fast: false
-    name: macos-14(Silicon)/java ${{ matrix.java_version }}-spark-${{matrix.spark-version}}/${{ matrix.test-target }}
-    runs-on: macos-14
-    steps:
-      - uses: actions/checkout@v4
-      - name: Setup Rust & Java toolchain
-        uses: ./.github/actions/setup-macos-builder
-        with:
-          rust-version: ${{env.RUST_VERSION}}
-          jdk-version: ${{ matrix.java_version }}
-          jdk-architecture: aarch64
-          protoc-architecture: aarch_64
-      - name: Java test steps
-        uses: ./.github/actions/java-test
-        with:
-          maven_opts: -Pspark-${{ matrix.spark-version }}
-          upload-test-reports: true
-
-  macos-aarch64-test-with-old-spark:
-    strategy:
-      matrix:
-        java_version: [17]
-        test-target: [java]
-        spark-version: ['3.4']
-        scala-version: ['2.12', '2.13']
-        exclude:
-          - java_version: 8
-      fail-fast: false
-    name: macos-14(Silicon)/java ${{ matrix.java_version }}-spark-${{matrix.spark-version}}-scala-${{matrix.scala-version}}/${{ matrix.test-target }}
-    runs-on: macos-14
-    steps:
-      - uses: actions/checkout@v4
-      - name: Setup Rust & Java toolchain
-        uses: ./.github/actions/setup-macos-builder
-        with:
-          rust-version: ${{env.RUST_VERSION}}
-          jdk-version: ${{ matrix.java_version }}
-          jdk-architecture: aarch64
-          protoc-architecture: aarch_64
-      - if: matrix.test-target == 'java'
-        name: Java test steps
-        uses: ./.github/actions/java-test
-        with:
-          maven_opts: -Pspark-${{ matrix.spark-version }},scala-${{ matrix.scala-version }}
-
diff --git a/.github/workflows/pr_build_linux.yml b/.github/workflows/pr_build_linux.yml
new file mode 100644
index 0000000000..732b5b4d15
--- /dev/null
+++ b/.github/workflows/pr_build_linux.yml
@@ -0,0 +1,165 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+name: PR Build (Linux)
+
+concurrency:
+  group: ${{ github.repository }}-${{ github.head_ref || github.sha }}-${{ github.workflow }}
+  cancel-in-progress: true
+
+on:
+  push:
+    paths-ignore:
+      - "doc/**"
+      - "docs/**"
+      - "**.md"
+  pull_request:
+    paths-ignore:
+      - "doc/**"
+      - "docs/**"
+      - "**.md"
+  # manual trigger
+  # https://docs.github.com/en/actions/managing-workflow-runs/manually-running-a-workflow
+  workflow_dispatch:
+
+env:
+  RUST_VERSION: stable
+
+jobs:
+  
+  # Run Rust tests once per JDK version
+  linux-test-rust:
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        java_version: [11, 17]
+      fail-fast: false
+    name: ${{ matrix.os }}/java ${{ matrix.java_version }}-rust
+    runs-on: ${{ matrix.os }}
+    container:
+      image: amd64/rust
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup Rust & Java toolchain
+        uses: ./.github/actions/setup-builder
+        with:
+          rust-version: ${{env.RUST_VERSION}}
+          jdk-version: ${{ matrix.java_version }}
+      - name: Rust test steps
+        uses: ./.github/actions/rust-test
+  
+  linux-test:
+    strategy:
+      matrix:
+        os: [ubuntu-latest]
+        # the goal with these profiles is to get coverage of all Java, Scala, and Spark
+        # versions without testing all possible combinations, which would be overkill
+        profile:
+          - name: "Spark 3.4, JDK 11, Scala 2.12"
+            java_version: "11"
+            maven_opts: "-Pspark-3.4 -Pscala-2.12"
+            scan_impl: "native_comet"
+
+          - name: "Spark 3.5, JDK 11, Scala 2.12"
+            java_version: "17"
+            maven_opts: "-Pspark-3.5 -Pscala-2.12"
+            scan_impl: "native_comet"
+
+          - name: "Spark 3.5, JDK 17, Scala 2.13"
+            java_version: "17"
+            maven_opts: "-Pspark-3.5 -Pscala-2.13"
+            scan_impl: "native_comet"
+
+          - name: "Spark 3.5, JDK 17, Scala 2.12 native_datafusion"
+            java_version: "17"
+            maven_opts: "-Pspark-3.5 -Pscala-2.12"
+            scan_impl: "native_datafusion"
+
+          - name: "Spark 3.5, JDK 17, Scala 2.12 native_iceberg_compat"
+            java_version: "17"
+            maven_opts: "-Pspark-3.5 -Pscala-2.12"
+            scan_impl: "native_iceberg_compat"
+
+          - name: "Spark 4.0, JDK 17"
+            java_version: "17"
+            maven_opts: "-Pspark-4.0"
+            scan_impl: "native_comet"
+        suite:
+          - name: "fuzz"
+            value: |
+              org.apache.comet.CometFuzzTestSuite
+              org.apache.comet.DataGeneratorSuite
+          - name: "shuffle"
+            value: |
+              org.apache.comet.exec.CometShuffleSuite
+              org.apache.comet.exec.CometShuffle4_0Suite
+              org.apache.comet.exec.CometNativeShuffleSuite
+              org.apache.comet.exec.CometShuffleEncryptionSuite
+              org.apache.comet.exec.CometShuffleManagerSuite
+              org.apache.comet.exec.CometAsyncShuffleSuite
+              org.apache.comet.exec.DisableAQECometShuffleSuite
+              org.apache.comet.exec.DisableAQECometAsyncShuffleSuite
+          - name: "parquet"
+            value: |
+              org.apache.comet.parquet.ParquetReadV1Suite
+              org.apache.comet.parquet.ParquetReadV2Suite
+              org.apache.spark.sql.comet.ParquetDatetimeRebaseV1Suite
+              org.apache.spark.sql.comet.ParquetDatetimeRebaseV2Suite
+              org.apache.spark.sql.comet.ParquetEncryptionITCase
+              org.apache.comet.exec.CometNativeReaderSuite
+          - name: "exec"
+            value: |
+              org.apache.comet.exec.CometAggregateSuite
+              org.apache.comet.exec.CometExec3_4PlusSuite
+              org.apache.comet.exec.CometExecSuite
+              org.apache.comet.exec.CometJoinSuite
+              org.apache.comet.CometArrayExpressionSuite
+              org.apache.comet.CometCastSuite
+              org.apache.comet.CometExpressionSuite
+              org.apache.comet.CometExpressionCoverageSuite
+              org.apache.comet.CometNativeSuite
+              org.apache.comet.CometSparkSessionExtensionsSuite
+              org.apache.comet.CometStringExpressionSuite
+              org.apache.spark.CometPluginsSuite
+              org.apache.spark.CometPluginsDefaultSuite
+              org.apache.spark.CometPluginsNonOverrideSuite
+              org.apache.spark.CometPluginsUnifiedModeOverrideSuite
+              org.apache.spark.sql.CometTPCDSQuerySuite
+              org.apache.spark.sql.CometTPCDSQueryTestSuite
+              org.apache.spark.sql.CometTPCHQuerySuite
+              org.apache.spark.sql.comet.CometTPCDSV1_4_PlanStabilitySuite
+              org.apache.spark.sql.comet.CometTPCDSV2_7_PlanStabilitySuite
+              org.apache.spark.sql.comet.CometTaskMetricsSuite
+      fail-fast: false
+    name: ${{ matrix.os }}/${{ matrix.profile.name }} [${{ matrix.suite.name }}]
+    runs-on: ${{ matrix.os }}
+    container:
+      image: amd64/rust
+    steps:
+      - uses: actions/checkout@v4
+      - name: Setup Rust & Java toolchain
+        uses: ./.github/actions/setup-builder
+        with:
+          rust-version: ${{env.RUST_VERSION}}
+          jdk-version: ${{ matrix.profile.java_version }}
+      - name: Java test steps
+        uses: ./.github/actions/java-test
+        with:
+          suites: ${{ matrix.suite.value }}
+          maven_opts: ${{ matrix.profile.maven_opts }}
+          scan_impl: ${{ matrix.profile.scan_impl }}
+          upload-test-reports: true
\ No newline at end of file
diff --git a/.github/workflows/pr_build_linux_spark4.yml b/.github/workflows/pr_build_macos.yml
similarity index 86%
rename from .github/workflows/pr_build_linux_spark4.yml
rename to .github/workflows/pr_build_macos.yml
index 0c143eb53d..85b40ac5b5 100644
--- a/.github/workflows/pr_build_linux_spark4.yml
+++ b/.github/workflows/pr_build_macos.yml
@@ -15,14 +15,13 @@
 # specific language governing permissions and limitations
 # under the License.
 
-name: PR Build (Linux + Spark 4)
+name: PR Build (macOS)
 
 concurrency:
   group: ${{ github.repository }}-${{ github.head_ref || github.sha }}-${{ github.workflow }}
   cancel-in-progress: true
 
 on:
-
   push:
     paths-ignore:
       - "doc/**"
@@ -42,14 +41,13 @@ env:
 
 jobs:
 
-  linux-test-with-spark4_0:
+  macos-aarch64-test:
     strategy:
       matrix:
-        os: [ubuntu-latest]
         java_version: [17]
-        test-target: [java]
-        spark-version: ['4.0']
-        suites:
+        spark-version: ['3.4', '3.5', '4.0']
+        scala-version: ['2.13']
+        suite:
           - name: "fuzz"
             value: |
               org.apache.comet.CometFuzzTestSuite
@@ -84,6 +82,7 @@ jobs:
               org.apache.comet.CometExpressionCoverageSuite
               org.apache.comet.CometNativeSuite
               org.apache.comet.CometSparkSessionExtensionsSuite
+              org.apache.comet.CometStringExpressionSuite
               org.apache.spark.CometPluginsSuite
               org.apache.spark.CometPluginsDefaultSuite
               org.apache.spark.CometPluginsNonOverrideSuite
@@ -95,20 +94,19 @@ jobs:
               org.apache.spark.sql.comet.CometTPCDSV2_7_PlanStabilitySuite
               org.apache.spark.sql.comet.CometTaskMetricsSuite
       fail-fast: false
-    name: ${{ matrix.os }}/java ${{ matrix.java_version }}-spark-${{matrix.spark-version}}/${{ matrix.test-target }} [${{ matrix.suites.name }}]
-    runs-on: ${{ matrix.os }}
-    container:
-      image: amd64/rust
+    name: macos-14(Silicon)/ ${{ matrix.java_version }}-spark-${{matrix.spark-version}}-scala-${{matrix.scala-version}} [${{matrix.suite.name}}]
+    runs-on: macos-14
     steps:
       - uses: actions/checkout@v4
       - name: Setup Rust & Java toolchain
-        uses: ./.github/actions/setup-builder
+        uses: ./.github/actions/setup-macos-builder
         with:
           rust-version: ${{env.RUST_VERSION}}
           jdk-version: ${{ matrix.java_version }}
+          jdk-architecture: aarch64
+          protoc-architecture: aarch_64
       - name: Java test steps
         uses: ./.github/actions/java-test
         with:
-          suites: ${{ matrix.suites.value }}
-          maven_opts: "-Pspark-${{ matrix.spark-version }}"
-          upload-test-reports: true
+          suites: ${{ matrix.suite.value }}
+          maven_opts: -Pspark-${{ matrix.spark-version }},scala-${{ matrix.scala-version }}
\ No newline at end of file