how are these spots? 4-8 hand

$4-8 6max

UTG limps, UTG+1 limps, MP raises, Hero is SB with :As:, and BB is most likely going to call

MP has a wide range

Hero ?

...calls.

UTG and UTG+1 will almost always call so you should probably call. Good odds for hitting the nuts.

it's 5.5:1.5 or 3.66:1 immediate odds and A6s is a great hand multiway in the blind for 1-1.5 bets. Folding here is too tight esp in a multiway limit game

Call it.

Fold.

Even if the MP has a wide range, with this many in the pot there's a fairly good chance you're dominated--and that's an expensive habit. As for making a nut flush, you're not going to continue on most hands where you flop a backdoor draw, and you usually don't get a ton of action when you hold Axs and three to your flush flops. That leaves the roughly 4% of the time you catch a flush draw and complete it, and where you're putting in additional bets in order to do so. I just don't see most pots, even with the pf raise, going to the neighborhodd of 20 small bets. To me the possibility of a nut flush (and the c. 3% of the time you flop two pair, three of a kind, or a full house) isn't quite enough to call the pf raise out of position.

by saying "dominated" you misunderstand what good A6s is multiway. catching a lone A is rarely good in this spot. The intent of the hand is flopping a 4 flush and playing pot odds after that. you're looking at the 4% from the wrong direction. If you don't catch 2 of your flush, you're not putting anymore bets and when you do catch 2, you are correct in continuing. flopping the nuts will definitely be called down by a K Q or J. Catching the 4 flush in this multiway pot will more than likely lead to a 10BB pot.