PLO2 Overplay AAxx

with flop SPR <4 your flop play would be fine. But with SPR around 8 you will never be in good shape when gettin checkraised equitywise:

thats your equity when villain check/raises sets, 2pairs, pairs+(2nd)nutflushdraw, wrap+flushdraws. you would have to fold vs checkraise but you dont want to because you have some SDV even though this might be gone really quick. but perfect to checkback, bluffcatch a turn stab from total air that would otherwise fold OTF and also strengthen your checkbackrange (last point might not be that important on PLO2)

SPR is actually around 6.5 or so I think. Yeah I would say your line would have been totally fine if villain just open raised pot and SPR would be bit smaller. I dont hate it now either as sets and better two pairs are quite rare. Of course villain will have QQ here fair amount of time as that is most likely made hand. Still stack off is bit awkward. But yeah we dont want to be bet-folding having bd fd as well. So check.

On this turn I would have called any turn bet. If villain had checked again I would then pot very often as delayed turn x-r are in general very rare in these spots.

another thing to think about: On this flop almost all top pairs have 3 side overcards to the 5 giving villain another 9 outs for better 2pair