They already have to have an NDA, so why not? If they are capable of being mod then they smart enough to help out on test. If they to busy with mod and don’t test much so what, even if they test 1 day a year but see something, that’s more info than before. In essence every little bit of info can help.
Regardless I mentioned mods along with the question of “do GPF get test build access”, of which you didn’t answer and I would like to know as GPF’s input to knowledge given will be different with or without it (edit: answer was given as yes by another), as Modmat established before when I asked that he didn’t have test, so I knew they didn’t.