It's more nuanced than that IMO.
The trick is to use FA off or on when the situation demands it, within combat.
If I was prevented from using FA off, I would be much worse in combat. If I was forced to use FA off all the time in combat, I would be much worse also.
Yes, you're right. I meant it with FA always off during combat. Even with vertical/lateral thrusters used at optimum efficiency I wasn't able to mimic the tight turns I get with FA Off.