Thanks for the answer! Funnily, I've been mistaken for Amish far too often, even with a mustache. Additonally, Chukas Akum seems to apply mostly to things that are immodest or (might) have idolatrous origins (
see here, neither of which would seem to apply to the Amish mustache-ban (which seems to be anti-military in nature). If you have a specific source for this, or a reason to believe that Chukas Akum might apply to beards minus mustaches (as opposed to, say, beards plus overalls), I think it'd greatly improve this answer. —
HodofHod yesterday