Not sure that 66 and ATs belong in a flatting range if hes really good and we'll be OOP, but could just be being a nit.

With his stats, it seems like we could be x/c a pretty normalish range flop and turn and then expect his river bets to be slightly unbalanced toward value, at least as a general plan.

In theory, I don't think he's likely to be going overboard cbetting this board, so donking with your continuing range seems decent to me...

With the reads and dynamics you gave I would try to build a check/calling and check/raising that both include draws and 2pair/sets. Usually I would just go for a checkraise here with a set repping sets and draws, but against an aggressive player and good hand reader it can be very useful to have a hand as strong as a set because once you just call that flop he will consider your range capped and put a lot of pressure on you.

I dont like the idea of donking our strong hands as this is something he can very easily pick up on, a simple note such as "donk set on drawy board" will remind him to make good laydowns without investing another cent and how weak your check/calling range from now on is. The latter one is true for the idea of checkraising as well, but Id go for something like checkraise the strong hands 75% of the time and checkraise a lot less (but not 0) with draws. As you sid his cbetting range will be really strong and therefore semibluffing goes down a lot in value while your implied odds increase.

As you can see m suggesting un unbalanced range that still keeps villain guessing, so a GTO player would completely disagree with me. Also I remember FoxwoodsFiend saying in a video that he would never checkraise 2pair or better in this spot, but unfortunately I cant remember all the reasons (it was higher stakes though, so the reason I mentioned that villain will incorrectly assign you a capped range is even more important).

I dont understand your reason for donking the turn though, it negates all the advantages of not having checkraised the flop.

i guesss u want to get val from worse hands till the board gets ugly so i d like x/r F
u can be happy that u got the blankiest runnouts ever
asplayed i guess donking turn makes sense if he gonna xbeh a lot of his draws and realise equity.. but often he might barell them and u can just x/r T if u didnt F

im x/c flop turn and x/r river. I think you lose a lot of value by taking this line and you got so many like bluffcatchers that want to showdown so not sure leading this big ott makes sense (?)

3bet pre. you are talking about balance when ur preflopgamle is terribly unbalanced cuz why wouldn't you want to 3bet JJ vs his 20/ opening range? doesn't make sense at all.

Consider donking medium strength hands / draw , xr a few 2 pairs and draws. try to count all the combo's and add frequencies. consider using flopzilla which is very usefull for these types of questions