[private joker]

I think check/folding a river 4 is pretty awful. If the EP call/3-bettor has A8 (as indicated by his turn play), a river 4 saves you. Q8 is an unlikely holding, and most people raise QQ preflop, especially at Commerce 9/18 (even though you describe the table as passive). Quads are an unlikely holding too, so I wouldn't put someone on 44 if a river 4 hit.

I do agree with check-folding a blank, but staying in with a Q, 9, or 4 (or obviously the case 8).