Hey guys i hope you can help me to find a solution / an approximation.

The situation: We are in the CO or BTN and a Regualr in MP opens for 3x. We have AQs - A2s and have to decide if we wanna flat or 3b.
We play vs regs for the most part. I think it's obv that if MP or the blinds are fishy we can flat much more profitable. I'm more interested in a solid strategy vs a Reg early opens and how we wanna measure the EV of our action.

I put some numbers / ranges into CREV to measure EV of a 3b:
MP opens 18-19% Range and
folds ~50% to a 3b
calls: JJ-55, KQs,AJs,AQ and 50% JTs
4b: AK QQ+ & all KQo, A2-A5s (50%weight)

and now we obv have to subtract the times we do get cold4b from the blinds and that is where i need to know how we calculate.

If MP calls or 4b we want to estimate R. What would you guys suggest ? If we get called i think we can realise a lot of Eq but if we get 4b and call a smallish 4b our R should be quite low. I would really appreciate some suggestions / numbers .

Now if we want to compare that to these numbers to a coldcall we have to use a more complicated model i guess.. we get squeezed much more frequently / we dont have preflop FE and no intitiative postflop and a low R. How would you guess compare the EV of these two options ?