PLO10 7654ss river bluff

I think the board is still quite static and as you have the straight-blocker and the 3-pair has nice blocking effects I would 2barrel the turn as it is hard to improve by the river and you have some FE and protection against hands like overpair, draws and/or bare top-pair.

Otr it is not safe to assume that he will fold all his 2pairs and he still might has a flush a decent amount of time as he would call many of those ott when he is loose, I would prefer to have a club-blocker to make a play here. Also a pot-sized bet is narrowing your range quite a lot (nutflush) which is unlikely to be in your range. If your villain is smart enough he will catch your bluff.

Well to be honest I would value bet at least Q+ flushes with pot. Why would I only value bet pot with such narrow range (nut flush+) in single raised pot with just single bet so far? It's pretty small pot.

Also flush being backdoor which will make it somewhat less likely for us to have it. Plus I think most are not aiming for river c-r which will decrease strong flushes from villain check range. So imo Q high flush is crushing villain call range also. If he does raise then I can think of folding weaker part of my value range.

I would bet turn too for protection and FE. And then check river.

I would value bet at least Q+ flushes with pot

I agree. Still it would quite narrow down your range