[Mr Rick]

I would value the hand as 8 outs, leaning heavily towards AhKh for UTG+1 and a smaller flush for MP (I think he has a boat <20% of the time), and I would call here. If MP caps then I would assume he has a boat which would still be worth a call when capped.

Taking the worst reasonable case, assuming MP has a boat and UTG+1 has nut flush leaves us with ~6 outs (7 outs to hit our full house but we would tie some of the time, and lose rarely to Q9 if a 3 hits). MP will cap turn so we would be putting in 3 BB to win 19BB + river bets. So its a close call given the worst case scenario.

I don't mind the pre-flop call. UTG+1 hasn't raised yet so getting heads up and re-raised against a likely AA, KK, or AKs is not what I want to accomplish with a 3-bet. Also, AQs plays fine multihanded. I wouldn't fold it either.

Edit: Against most players who have a wider perceived range I will re-raise pre-flop with AQs, in most games (my 10/20 games are usually not tight/aggressive). Ed Miller suggests calling with AQs in tight games, raising in Loose games, in EP.