I think that even if his range is wider, e.g. 6.33% (99+, AQ+, KQ) I think stacking off on this flop is not such a good idea.

Assuming that #1 when we c/r we commit and stack off and #2 he folds all his air and calls only OP then:

2.71% stacks off (99+)

3.62% fold (AQ+, KQ) - 57% FE.

57% cases +$1.65.

43% cases we have 36.16% equity

Stack off (win) = 12.01 * 0.3616 = +$4.34

Stack off (lose) = -$5.33 (what's left in our stack)

Total: 1.65*0.57 + (4.34 - 5.33)*0.43 = 0.94 - 0.43 = +$0.51 (+5.1 BB)

If the assumptions are correct then stacking off is profitable

I wonder if there is a way to calculate an EV of calling

If his range does not include KQ then:

We have only 47% FE

47% cases +$1.65.

53% cases we have 36.16% equity

Total: 1.65*0.47 + (4.34 - 5.33)*0.53 = 0.78 - 0.52 = +$0.26 (+2.6 BB)

It's still profitable.

Therefore, check/raising is +EV here

please correct me if I made a mistake in my calculations.

EDIT: Corrected winnings when he folds from $2.65 to $1.65.