Kinda depends on how you plan to play the hand post flop. If you're just going to play fit or fold on the flop, then perhaps 3bet>fold>call.

If you have confidence in the edge that hand strength + position gives you against this villain then you should want there to be more room eg, larger SPR on the flop. So if you plan to raise any flush draw, and call with any marginal hand as well as occasionally float or raise his cbets even when you miss then this becomes much more favorable than 3betting. You're going to pair the flop 36% and flop a flush draw another 8% - sorry if these numbers are a bit off - and you have to figure you can float/raise and use position to pressure villain at least 20% of the time with air or just overcards.

Not sure if I'm explaining this properly but I know I learned the concept in NLHETAP.

The main reasons for betting and raising are for value and as a bluff. Taking medium strength hands that can flop well and turning them into a bluff is wasting the huge potential for value when played for a small preflop investment. Since we can't profitably call raises with ATC but we can profitably 3bet light with any two, then it seems more sensible to save our bluff opportunities for hands that are no good to flat with and flat with our medium strength hands.

If you 3bet ATs+ in this spot then it is hard to incorporate more junk hands into your light 3betting range without being exploited by light 4bets. If you keep your light 3betting range limited to junk, then villain is going to be up against premium hands or complete junk when he decides to 4bet or flat your 3bet.