PLO25 JJ77ss optimistic bluff?

Versus one player it would be fine at least on the turn, but versus two the fold equity is cut in half. Numbers don't back it up.

It seems like you got in trouble here because of the preflop raise. The problem is you have a middling double pair that is not connected and there are 2 limpers instead of 1. JJ77 is not the easiest hand to play perfectly out of position 3-way because there are so many boards when JJ has value in theory but you end up check-folding or giving up later (like this flop for example). I would just complete the blind and raise hands like JJ78 instead.

On postflop I agree with Kyyberi. Thinking of your line, what are the value hands in your range after the river bet? For me it feels like you are block betting something that isn't a flush but I could be wrong.

I would bet hands like 9, T, J high flushes like this. WIth K♠: or Q♠: I would likely go for bigger sizes whatever I have it or not. At least on river. Turn half pot is kind of nice with nuts as well to try and get action from two pairs.

Preflop I raise for set value mainly to have pot build up already if hitting.

I think one thing to note is also fact that flop goes checked so for villains K♠:xxx combos are less likely. Not big deal though as those limp ranges can have small flushes as well. Kind of reason why I think value betting those mid high flushes for two street is totally fine.

It's the double 1/2 that makes this weird for me but if it's the line you always take with 9s, Ts and Js then I guess it's fine. It just makes your range narrow. With bigger sizing on either of the streets you could have more bluffs and nuts in your range as well.