I’m working on the same sort of issue for a plugin in Unreal 5.3
I found the documentation that lists the members but I would hardly call that documentation … more like list of members … 
Is there any documentation that breaks down the .uplugin and shows its use cases as the file self
I managed to get it limited to Win64 … but attempting to add Linux and Mac to that causes it to build for Droid again
I would love to see a list of what the valid values are just guessing based on what I see elsewhere RE platform labels