Hi guys, I'm trying to build my call-4bet ranges when I 3bet linear, and I'd like your thoughts about some concepts.

First of all, the R, meaning the percentage of equity we're gonna realize,
I calculated the R of some hand-types needed to make the call EV0, based on their equities against my 4bet range of CO (assuming we 3bet linear in BU) :
AQo-TT (R=0.6) > AJo-99-88 > KQo > ATs-JTs > 78s (R=0.85)

I guess when we have an R<1 the call is easily +EV, especially in position. The things that can make our call -EV is the reverse impled odds we have given we'll play against QQ+ a large % of time, and the fact we'll fold the best hand sometimes.
Another thing important to consider is that the SPR are very low, so I guess there are less implied and reverse implied odds, then the R will vary less than in 3bet pots. Do you think we can have the R needed with those hands or the reverse implied odds are too important with hands like AJo KQo ?

I'd also like your thoughts on the "call multiplier", I mean by that the extra % of hands we have to call with to defend against a 4-bet as effective as a jam. Here's an example, CO opens, BU 3bets, CO 4bets, if we jam we prevent CO to realize any of his equity with his 4bet bluff, because he won't see any flop. When we call 4bet to defend, he'll realize some of his equity, so we'll have to defend more when we call than when we jam. So let's say we 3-bets 10%, CO 4bets, we have to defend around 45% of our 3-bets, so 4,5% : We jam 2% of time, then there is still 2.5% to defend, and we assume we'll have a call multiplier of 2, so we'll call-4bet 5% of time.

I guess the call multiplier should be higher out of position than in position, as vilain will realize more of his equity with his bluffs in position, and I also guess that the call multiplier should be lower in 4bet than in 3bet pot, given the SPR is smaller so the implied odds are smaller.
In 3bet pots I saw a lot of people using a call multiplier around 2 and 2.5. Do you thing a call multiplier of 1.8 would be good for a calling-4bet IP ?

Thanks a lot for sharing your thoughts guys