I think is a pretty straightforward 3bet, no reason not to 3 bet with those kind of stats and KJs is a prefect hand to do it with. Even if he calls we have the postflop position and the iniciative in the pot and we can flop very well sometimes. We obviously fold to a 4bet so it's not like it would be a tough decision.

As for the flatting range I guess I would do it with AK, AQ and AJs and AA-QQ (even though I'm not too fond of doing this with the high pocket pairs, just bad personal experiences of getting outflopped or outdrawn on later streets). We still don't want to flat JJ and TT since we have to protect our hand as we are not sure how we're doing on any flop wih overcards. I guess that's about it.

Also that is a lot of HUD

Holy HUD Batman!

You can either 3bet or flat here, I'd lean towards 3bet.

I'm not sure but it looks like you have 203 hands on villain which isn't a ton. I'd expect his fold to 3bet isn't entirely accurate due to sample size. Even if he was folding a ton I'm still not flatting monster hands here unless the blinds are squeeze happy. I would start to open up with a lot more bluffs though.

That table looks like something in the matrix.

Both options are fine, if they are very aggressive post flop and the blinds like to squeeze, then a 3bet is ideal. If the blinds are passive and the reg plays pretty ABC, calling is fine.

If we had KJo I'd almost always 3bet.

Glad you liked my HUD. lol
I have now also included RFI for every position so now it´s even bigger.

Anyway, thanks for the feedback.
Looks like both 3bet and flatting are correct so I will probably use a mix of them.
It also make sense to sometimes flat AK, AQ, AJs, AA-QQ but mostly 3bet them.

KJ os I prefer to 3bet bluff and KJs I prefer to just defend my BTN with as it flops better post flop.