Seems like an extension of the "do electros ruin semi play" or "do semis ruin pump play" controversies.
I guess if you had a tourney where everyone who played had F/A then you could see if it was viable - would it be entertaining to watch, or would everyone hide behind their bunker as their opposite number burped through their hopper in 10 seconds flat, before reciprocating until they'd both exhausted their packs?
Hell, it might work, you never know! As far as mixed games go, then if the laws were relaxed I'm sure pressure would be brought by some of the teams and promoters to allow play with F/A if they felt it would give them an edge over other teams.