The official modulargrid admin has provided the solution: consolidate modules that are functionally the same but merely have different faceplates, and just use the provided Panel Selector tool to switch between versions.
https://www.modulargrid.net/e/forum/posts/index/11176
-- sibilant
You'll note that I linked to that thread above. From that post:
chaos215bar2PM Posted: Jun 8th, 00:30 Quote
It’s a problem when you have multiple racks. See above.
That was not addressed. If the panel selector doesn't work across racks, and it doesn't even work when copying and pasting a module across racks, then it is not a sufficient solution. This would be why many manufacturers continue to add multiple panel options as separate modules.
If panel selection can be made "sticky" per module per user, that would be fine, and duplicate versions of modules could be cleaned up. That would help a lot with database efficiency.
As it is, I've had modules change in existing racks, and as you can see in the other posts I linked as well as the one you linked, so do other users. Manufacturer's submissions get overridden unless locked to the manufacturer... which leads users with alternate faceplates to create duplicate modules. Same problem again.