I don’t think it is; BS01 archives canon, but they don’t get to make decisions on it.
Right now, there’s no objectively correct answer; every Greg Quote about the Mahri masks includes something like “as far as I know”, or “at least this many changes”. While it’s possible that the official Faxon piece is the standard shape, it’s also possible that it’s not, and we can’t know unless Greg gives some clarification. He’d probably be more willing to give a definitive answer if there’s an actual alternative to the standard piece, rather than having to say “the parts aren’t standard and I don’t know what is”.
Personally, I’d prefer that the standard Faxon didn’t have sockets for tubes and lightbulbs that aren’t part of the standard mask, but that’s not my decision.