A4s on BU vs utg open, flopping flush draw

Villain has a 6% PFR. How big do you think is his open from UTG?
Call is awful, not only for this, but because of the active player on BB...
3B is a bit too much preflop.

I think this is a valid point. BB´s sample size is too small, though.

What is your 3betting range on BU versus UTG open?

Well for 69 hands BB showed aggression, so I prefer to be cautious.

I won't tell my exact range for 3b BUvsUTG but I have a value part and a bluff part.
In w34z3l's Walkthrough he gave as an example this:
BBvsUTG KK+, T9s, 98s, 87s, 76s, 65s

Fold or 3bet pre. Fold flop. Maybe even fold turn.

Preflop: He opens 5bb. Too much for me to raise. A call can be motivated by his 138bb stack that you cover. Looking closer on his stats, it is a call. He'll probably lose his stack with one big pair.

Fold flop. Too vague prospects.

Turn: You have 7+3 =10 nut outs. This is pretty much the minimum for calling turn given a 100% guarantee that he stacks off. In the best case, you have 12 outs. I think this is too optimistic.

I would fold preflop vs that size. When called, I would fold the flop vs that size. We don't have a very good draw and enough outs to call giving the pot odds .