hello there mkjmkjmkj
Here are my 2 cents.
If you play vs villain who calls a lot of 4 bets then there is really no need to 4bet bluff. The same thing apply to 3bets. Why would we 3bet bluff if we know that villain will call it.
So we can do 4 bet for value. That mean that our 4betting range is stronger than his 4bet calling range.
We would like to 4bet as a bluff because we know there is enough fold equity. Basically we do want to 4bet bluff when our range is to weak to call 3bet and we generate enough fold equity (we do not want to turn our hands which are stronger than his 3betting range into a bluff). We can make fold equity even higher when we do have a blocker card. Suited Axs Kxs maybe Qxs are great candidates.
So vs player who calls a lot of 4bets no hand is good to bluff. Of course table dynamics can change that. First he folds to 4bet bluffs than he adopts. You also have to adopt on his play and so on.
I am far from a pro player but i still hope i answered a bit to your question. On the other hand i hope i will also provoke some good next posts.