I think this could be very player dependent. I think a lot of the times he has you beat there, but it depends a lot on the player.

E.g. some people get scared and xr all sets/top two on flops for fear of getting sucked out on. Others like to call - donk to throw opponents off.

The fact it was a diamond that landed and he donked in opens his range (IMO). Tbh I flat here and see how it is played on the river. I think it could be hard for him to barrel the river as your range has so much of board. Even diamonds/paired boards are bad for him to barrel (unless he has good blockers) due to once again potentially hitting you so well.

Also you having two blockers to QT I think there are more pair+combo draws in his range, with some sets afraid of a xback.

for sure, its player dependent.regs could c/c set and lead it ott, but it is NOT the way most would play. if villain not w\ above 45% turn aggression and  I now note "donk ott-donk otr w\ blockers" I would probably give up on the turn, as a) we've been opening utg, which means we almost always hitting bord really good, which makes him unlikely to bluff. b) we have no appropriate plan for the river and too few outs to improve (unless we're putting him on str8 and gonna bet\raise any paired river)

all in all, for me its fold, but heavily depends on opponent. 

frankly saying, idk how much we should accent on blockers here. it shortens #of nut combos, but still..

That makes sense, but what do you put his hand on? We have a lot of card removal for combos like QJ10x, AQ10x, KQ10x.

I definitely think if you are calling here you have to be able to turn your hand into a bluff on certrain rivers if you think it needed.

Is he really donking river when it pairs or flushes with a straight? what is your perceived range here?