Owner of /build folder in container

[martinkunkel2]

Background:
Vscode/devcontainer framework is executing a user mapping, so that the uid of the ebcl user in the container matches the uid on the host. This also updates the permissions of the home folder: https://github.com/devcontainers/cli/blob/7178cebfa88e070439903fd975b7602e7b3f6dc7/scripts/updateUID.Dockerfile#L31

Problem is that other folders are not updated, so the /build folder is still owned by the original UID of the ebcl user.
Example from my setup:

host:
uid=1000(martin) gid=1000(martin)

container image ghcr.io/elektrobit/ebcl_dev_container:v1.4.4:
uid=1001(ebcl) gid=1000(ebcl)

in vscode devcontainer:
uid=1000(ebcl) gid=1000(ebcl)

but the /build folder is still owned by 1001:

(venv) ebcl@ext_ebcl-adg-app:/workspace$ ls -la /build
total 40
drwxr-xr-x 1 1001 ebcl 4096 Dec  2 19:10 .
drwxr-xr-x 1 root root 4096 Dec  3 15:47 ..

Is it a problem that the user can now not write to /build?
If this is not a problem, then: can the /build folder be owned by root?