Not sure how mergy ppl tend to raise flops in your environment. But therefore you bet over half pot otf in theory villain should raise a more polarized. That’s said we have somewhat WAWB situation OTT and therefore i prefer checking.
What’s your reasoning for betting here? Value? Bluff?
What would be your plan facing another XR OTT?

This hand came up in today's session and I am unsure about my turn play here. So on the flop I perceive Villain's range to be heavily biased towards bluffs as his value range consists of merely 8 combos of sets and occasionally 64s, whereas any Ax or 6x might raise its gutshots here. The turn further reduces his possible value combos.

This isn't really correct. Not only is A4 also possible but BB should raise a bunch of his 5x and other paired hands here. It's not so polarized to 2 pair or better.

But your hand is still strong and a bet on the turn seems good. Sizing is also fine, no need to go bigger.

I play the hand same as you, I want to protect equity on the turn (I am expecting to be mainly ahead when he checks) and I am folding if he x/raises again. We are also buying a showdown rather than having to call a river bet when we don't like any rivers.

He can have all sorts including 43 45 random 4x many 5x and 6x as well as the monsters.