Bad stackoff for sure. Without specific info on villain You should avoid calling 3bets preflop with KQo.

I put him on AA / KK preflop, and so even after you pair up on the flop you are still beat. I probably would have just gone into quiet mode and checked the turn, folded on the river if I didn't hit another Q or a K. Not saying that's the best thing to do, but just thinking out load.

Your line looks so strong but you never ever fold out better. Checking back turn and calling a river bet is much better.

It would be horrible to call this preflop and not stack off here.
Kre8r he says villain is a light 3better so thats specific info whcih makes KQ playable here for value.

I can definitely see the argument for checking turn and calling river being better, or even betting soemthing silly like $10 to get called by a hand like AT or 99 which may fold to a shove or even to try and induce a hopeless shove. However if he shoves the turn on even a non-diamond and we are not snap calling we should have folded preflop.

I like checking back since a free card is more likely to help us than hinder us. Only really a non diamond ace and to a lesser extent a non diamond J or 9 really bother us. And if a 4th diamond comes and he doesnt have one good chance he tries to rep it anyway.

I didnt read the title that said he was a light 3better. My bad. If thats the case then like Wota said, its probably okay to play it this way and stackoff.