I have a question about playing weak ace off-suit
in coaching video, it says weak ace offsuit is not great hand to flat
he 3bet bluff with it rather than flat

Now, my question is, 3bet bluff against both of BTN and SB?

Some players flat with weak ace vs BTN but 3bet vs SB
How they are different?

IMO, the reason of flat vs BTN is it is hard to play OOP and we don't want to make pot bigger
however, vs SB, since we have positional advantage, it is much easier to play with weak ace
For example, if i 3bet with A2o and villain call
i hit the ace otf. in this situation, I wanna go and see showdown cheaply as possible
if i have a position advantage, it is easy to pot control but OOP, it is kind of hard.

if villain triple barrel, almost every time i should fold
but in position, i can check-back otf and decide ott and otr

do you think it is better to fold than flat with weak ace offsuit vs BTN?