PLO25 QJT9ds triple barrel?

I'd check the turn as I don't think you have a lot of foldequity after betting the flop big.
Your conclusions about balancing are correct in theory but if he calls too wide preflop he is unlikely to know how strong your range is and he is unlikely to make hero folds because of it

If you bet the turn, you have to bet the river. But not sure if you need to pot it, unless the opponent is good enough that you want to pot your bluffs and nuts.
Your hand history is a bit different than your text. On that hand history river is potted, not 2/3.

Yeah but villain only has around 10€ behind. This one did work and villain folded. Well I was hesitating about turn and without extra straight outs I would have very likely checked. We do have 9 nut outs though so if villain bet less than pot we are getting into x-c territory pretty quickly.

Problem is that turn doesn't change anything, so FE is a bit low. And if you miss your 13 outs, you end up trying to make him fold a made hand on a blankish river. Or on a club river it's not a good spot to barrel.

I would check and see if you get a free river or opponent gives good enough price.