if you've been 3-betting him already, isn't this the perfect set-up hand to 3b/snap? i like it up to now and think we should bet about 15k to get value from KQ and AT-type hands. yes sometimes we will be value-towning ourselves but if we're never doing that then we're really not v-betting thin enough.
edit: even if he never calls, it's better not to have to show our hand down because it generally makes us harder to play against.
Everything looks fine, and if I bet, it would be about 16k.
You want to get value from as many hands as possible, and betting more is going to get marginal hands to fold. You don't want to bet so much that you cut off the bottom of his calling range, especially when it's so likely he has little or nothing.
Also, if you're the soulreading type, 16k is far more likely to induce a bluff-check-raise than 30k.
Villain has like 62k left on river with 43k in the middle. I think if you're going to bet like 30k for value you should just shove, because he's going to call with worse pretty much just as often as he'll call a bet for half his remaining stack, or at least often enough in comparison to make it more profitable. You might even induce some more heroic calls that way.
So yeah I think if you bet river you should either go really small like 18k or something to entice some reluctant call, or just ship it in and hope he heros