I think you can remove AA from his range entirely tbh due to his flop play. I'm not saying that flop action like this means it's never AA, I'm just saying that flop action like this at PLO5 means it's never AA.
I also think that "-We get bluffed out on river by non flush" is a moot argument since we are talking about the odds for calling turn vs a range that is massively weighed towards being a flush. I'm trying to articulate exactly why but can't come up with the proper way to write it out in English (Swedish too for that matter lol).
I see your concern and the range calculations and you might be right (I'm wrong pretty often
), I just don't think it's a good fold ott at plo5 for that price.