Villain is very active at these stacks (40/32 with 3.0 AF) but only over 25 hands. No specific read, I assume they are a random fish.

Very straightforward, nothing to say here.

Sizing is designed to set up future barrels on good runouts.

This feels like one of the worst cards for me to barrel. I was torn between choosing not to barrel because I have no blockers to villain's diamond combos and it's a card that's totally un-scary for the wide flop calling range of a loose villain, versus barrelling here because it sets up a good triple barrel spot against a fairly weak range. The thing that always runs through my mind is that there's a difference between knowing a villain has a wide/weak range, and being able to get them to fold it.

I can't really figure out what villain's bluffing range could be here. Obviously 98 got there, QJ/QT got there, AQ got there, Q5 got there...villain would have to be turning 5x into a bluff here or check-calling flop with a hand like 87 for me to be good, and I'm not convinced the frequency of that is particularly high.

I do have some better hands in my range here on the river - AK, AQ, QT, some frequency of QJ maybe, perhaps even some Q5 if I bet those on flop - but KQ is obviously beating any bluffs. I'm curious what you guys think of villain's river sizing and whether we're ahead often enough to make the call here.