I'm interested in theorycrafting an MP 3betting range and wondered if anyone here has done much work on the subject?

For some time I've been using a tight and semi polarized range comprised of pure value (AA,KK,AKs, some QQ) and some hands that would be marginal or losing cold calls (such as ATs, KJs, QTs, J9s), with a pure 5bet AI or fold strategy versus a 4bet. I think the range I've been using is on the tight side but pretty good.

However I've noticed that some of the 6max end bosses seem to be 3betting a little wider and with a more linear range - for instance 3betting some JJ, some AQs, and then defending against 4bets with a flatting and 5betting range.

All thoughts appreciated.