Do we need to condition this with a 'back out' flag? I assume it won't do anything bad to have it on, so probably not?

Yeah, project capabilities don't do anything, they're just like attributes you attach to things. In this case, given this file is only used in the C# Extension, even adding the capability is redundant, since it doesn't do anything and nothing cares whether its there, but its easier to have the files matching :)

but its easier to have the files matching :)

Is there a way to avoid the copy/paste of the file? Or if not, can this at least link to the other file somewhere so somebody knows when to update one they can also update the other?

It is linked at the top of this file (at least, I think I remember doing that, but I'm typing this on my phone so who knows!)

You linked to the whole file, but that's a somewhat different flavor. Not sure if that repo should minimally extract a file out so some file can be the same, or whether we should just adopt that file into the C# extension project system directly.

Logged #12137

But who can edit this file if only those knowledgable in MSBuild can edit it?

Thats why I created the file, because I'm not qualified to modify it 😁

but its easier to have the files matching :)

Is there a way to avoid the copy/paste of the file? Or if not, can this at least link to the other file somewhere so somebody knows when to update one they can also update the other?