AKo low flop 3bet pot

It was a cold 4bet instead of squeeze. Assuming you wanted everyone to fold with weaker hands and win the pot immediately, I think your size was OK.

After you 4bet to that size, you were already pot committed vs this medium stacked opponents. I don't worry too much about his range otf anymore. With AK, 1. it was possible you have the best hand here 2. you have two overcards. I would just jam like how you played.

MP 3b vs UTG is going to be the tightest 3b range (aside from sb 3b vs utg) you will face in 6 max. This is usually TT+, AQs+, KQs and maybe a bluff or two with some suited wheel ace.

I prefer to call here pre and play a pot. You have a nice equity advantage vs. his Ax (assuming he bluffs some wheel aces), can out-flop KK, slight dog to QQ-TT and dominate KQs (if that is even in his range). You still have UTG reggish looking player in the pot so I can see why you want to raise here but he isn't likely to call in this spot plus you have position and can get away if he ships and MP calls.

I like this play better with AKs since you will have about 3-4% better equity vs. this tight range. Also, you can size down some if 4bet is your option and give yourself some more wiggle room.