So, having said all that, it somewhat concerns me that villain didn't shove, if he is really bluffing and understands that we understand ICM
Yeah, I agree with your point, but that assumption is most likely untrue, even most regs dont take ICM into account here, so him assuming that OP doesnt take ICM in mind is very likely
calling could look like a sucker choice but we are always getting a cbet if we flop or c/f mostly. you can never define a range for his 3bet in my opinion, it is a leveling spot.
Don't like it in this spot. Maybe if our stack was 35BB's+ and all other things were equal. If you aren't opening to 4-bet jam then just open jam. Might prefer open jamming if we think he is going to re-shove wide on us given stacks because then we would need to fold. Someone said fold pre and that is an absolute joke.