The best disguise is one you don't have to think too hard about, and that can't easily be removed. False moustaches and stuff like that are just asking for disaster. Often humorous disaster, as seen in multiple comedies.
Of course in a game you can go either for the serious or the comedy approach, so false facial hair definitely has its place. Right up there with three kobolds in a trench coat pretending to be a wizard. (Which is a classic, by the way, if you've never used it.)
Commentary by memnarch (who has not seen the movie)
Whoa, I wasn't expecting we'd get that reveal this soon. Which means we've still got the Poe-is-a-traitor subplot; huzzah! Wait, that's not really a good thing. Assuming that Jim remembers that part of Poe anyway. I bet the GM and/or Sally won't forget though!
I guess Kanata must have finished his bar fight or whatever it was? Taking the goggles off in the middle of a fight seems like a bad idea. Or maybe it's just meant as a little dramatic gesture and there isn't any extra thought put into it. Definitely fits with everyone else looking at Jim as a "what a crazy idea" face!
Darth Kanata: I escaped my doom by pretending to be someone else too. Worked for a while, but the past has a way of catching up with you.
Allan: Okay, okay! I confess! I don’t have twin triplets! I didn’t die in that crash on Tatooine!
Finn: You’re Poe?!
Poe: Yeah. Clever disguise, wasn’t it?
Finn: How did you survive the crash?
Poe: No idea. I just woke up in the desert. No sign of the ship or you.
Finn: This... this is unbelievable!
C-3PO: Less believable than him having 1.5±0.5 identical siblings?
Poe: Stop pressuring me! I was Doomed from passing BB-8 the map to Ahch-To! I needed a way to cheat Fate!
Darth Kanata: Huh. That’s not what I was talking about at all.