Wonder if turning top two into bluff was too much? Open BU, BB call. B50 flop, B100 turn and B100 river, Well opponent might be tight enough to also fold some flushes on river. My idea was that villain has some flopped sets. A5 is very often just calling and 65 with no back up likely also play passive.
I would love to have good old PokerJuice for this one. As you beat still a whole lot of his range. I don't think he ever calls with worse, so it's about does he fold more than half of the range that is beating you. If you estimate that he has straights also in his range more often as flushes, then I think it's ok. He does have backdoor flush quite rarely compared to sets/straights on the flop. But mainly the question is how often he takes passive line with a straight.
I don't think he should fold his backdoor flush that often, if he calls the turn with it. You were aggressor from the flop, so your range should have some missed fd's too that need to fire river to win the hand.
Yeah I dont think any flush should fold theory wise but also this fellow rarely does make hero calls. I would assume theory wise we are betting most flushes on river but in this case I would prolly only value bet like 3rd nut+. That said I would not bluff with busted nfd unless its specifically with 66+diamond blocker. I think my hand does make ok bluff on blank as well having only weak fd and having two straight blocker.
In old school PLO (time before backdoors were an important part) your story changes and opponent should consider bluff catching on the river. 
In modern PLO we care a lot more about backdoors as they gives us more playability on turns and chance to use more aggression, and an easy way to put balance on our ranges without overthinking it too much. Which means that aggressive lines actually hit backdoors more often than in the old school.
