No relevant reads other than villain looks like a reg.
The solver says preflop is a marginal call.

I tank called river because a pot river donk in multiway pots should be a very polarized range of nuts and bluffs and I am holding Kc so I suspected villain would be most likely turning a 2p or set into a bluff here. Vbetting a J high flush is of course possible but I would think that a lot of players, especially at these stakes, would size down a bit or check. But that's just me guessing based on my experience in other formats.
So do you call, fold or shove?

Gotta bet the flop. Perfect blockers to bluff. If not this hand what do you bluff on the flop?

I'd pot the turn, and see river as mostly a raise or fold.

I don't mind flop check, but betting small is reasonable, different strategies are possible.

I'm also guessing pre-flop plays better as a raise than a call? But here solver norms may differ from population.

Now that I think of it, I'm pretty sure that I underbluff A high boards as the caller so thanks for pointing that out.
I would have bet something like KJTx but check most A hands because I have some sdv
Do you not prefer to have a fd/bdfd here for bluffing?

I use plogenius and the only combo that 3 bets there is the double suited one without the nut suit. The quad suited and worst single suited combos fold and the whole rest prefers to flat. Recently I've heard that plogenius can be inaccurate though

So 3way in 5 card you can’t look at it in that way. You can’t bluff this flop without sd value because it’s suicide to bet without the A blocker into 2 people.

So a hand like KJT has more equity but remember that choosing bluffs is not about choosing high equity hands necessarily. Choosing bluffs is picking combos that are higher ev in the betting line. KJT is high equity, but it’s also high equity as a check.

This hand is the closest we have to a pure bluff. The future street blockers to the nuts are more valuable in a larger pot and so higher ev in lines that lead to a large pot > flop bet.

Now let’s say we have not just the Kc blocker but another club to go with it for a NFD. Is that a better bluff? Not necessarily. It’s simply a better hand.

What about AQK55 with the Kc. Is that a bluff or a valuebet? You can see the line starts to blur because of the nature of 5 card plo.

Also preflop is not good as a 3b because trip suit makes the hand difficult to play for that kind of SPR: you’ll flop 3 card non nutted fd’s which you can’t play aggresively on the flop. This is problematic for a 3-5 SPR, you flop overpair and 3 card k high FD, you can’t bomb it well, or what if you flop 579ssx and your opponent pots into you?

I could see him having a flush draw + 1/2pr on the turn here, hence he decided to x/c. You would need him to turn something like AJ/QJ into a bluff here and I don't see it - on the flip side could you jam here and get him to fold given your blocker? I find that interesting - I don't know if he would fold J/T high flushes but it sounds plausible.

Always ship the nut blocker in 5 card unless stacks are really short or villain is special.

It seems to me now that in general in 5c PLO, we almost always have relevant blockers in like every area of the game tree so we should always look to have a pair/flush blocker etc and play other hands more passively. Especially multiway where our betting range is more narrow so there's no reason to bluff the inferior combos.

About shoving the river, the way I think about the game currently, I call with the straight+ Kc if I suspect villain is bluffing and would have probably shoved the naked Kc. But I can get behind the idea of shoving any nut blocker because I see guys just snap folding to river raises all the time.