I would fold the river as played but think the lead is pretty bad. He's much more likely than you to have the bd flush and will try to rep it some of the time, and the fact that you don't have it very often also means he'll feel free to vbet thin, i.e. some worse hands than you.
I felt like he might call this with hands as weak as AK though, people seem to play bad vs river leads but given he is probably better than average on 888 your probably right. I felt like I could get a bigger bet out of him then he would bet himself with value hands if that makes sense. It does stop any bluffs though which might not make up for the extra few hundred the lead gets out of him.
Still working on correct spots/sizes to lead here so it wouldn't surprise me if it was bad.