Hi Andy,
You write that you changed from ElagantOTA to ESPAsyncHTTPUpdateServer.
In Method 1, item 8, you write to change some lines in ElagantOTA.h but you moved away from Elagant ....
Before I try to flash another ESP32 module according method 1 I would like to be sure that your text is correct.
Best regards,
Bernd
PS: Since your memory update my 2x ESP32 works like a charm.