When he's check-calling OTT it looks like he has a decent piece of this board, and I don't think he's willing to let go of it on this brick river unless you make it really big. It's a wet and dynamic board, and while he should already be pot-controlling with most of his range on the flop, he might have decided to start doing it on the turn instead.

I really don't know enough about overbetting rivers to give good reasons for it or against it, but I know enough about a standard bet-sizings to know that it's probably not going to yield the results you are hoping for on this river.

If you look at your own range there is really not much you want to be value betting with on this river except for maybe the few nut flushes AQd-AJd, KdJd, KdQd, QdJd.
Speaking of nut flushes, the Ad would make a terrific bluff candidate on this river. Much better than QsJs in my opinion.

I think you even have a little bit of showdown value and I expect almost no fold-equity. You also block part of villain's folding range otr. So therefore I think that checking/giving up is best with this part of your range.
Any bet you make is likely extremely polarizing anyway therefore an all-in OTR is probably the best line for your nut-diamond blocker bluffs, and and also best for all your nutted value-bets.

Hope this makes sense.-)

Agreed with most of Kuduku's post. Villain's most likely hands here are Kx and potentially sets so we don't really want to have both a queen and jack in our hand as they block combos that are likely folding river. As Kuduku said, we'd love to bluff with the Ad here as it blocks AK combos as well the improbable nut flushes that play this way AND we don't get bluff raised very often when villain can't have the nut blocker.

just wondering what Ad does hero have in his range? AQ? I feel like I raise/fold with AJo/ATo pre and sometimes 3b AQ so that doesn't leave many Ad in the range to bluff.

Everybody told you not to bluff here and that's true, but I really didn't like the point of valuebetting only flushes here. For this sizing we can definitely bet KT+, which has ~70% of equity here.
Another thing is sizing, betting 3/4 pot accomplishes nothing in this situation since your value bets still have >70% of equity vs calling range -> want to bet bigger size and you have plenty of bluffs, with bigger size you can bluff more.
My advice is to bet 1.5 pot with KT+ (still he will call Kx with diamonds sometimes and you have ~55% of equity) and greatly overbluff this river (he will need to call AK+ for you to lose money)