very cool and good, more antags is better, for one can not become robust without practical experience
if you desire a gamemode, surely it isn't that much of a stretch to participate in the round as that mode's antag
however, I foresee potential issues with people not wanting to be antags, and thus not voting, resulting in a lower amount of votes in general. this could also potentially bait newer players if not fully elaborated. perhaps in the voting menu, some big ol' text saying "voting = you could be the antag" would be nice albeit it is not necessary by any means
but in summary yes very good i like this idea