Originally Posted by
pineteam
On A320 family it’s not recommended with flaps 2 probably because of a potential wiggle.
I believe it is because the tendency of the airplane to roll.
The limitation to use speedbrakes with flaps extended might have something to do with an engine failure. If you lose a donkey with full flaps and the speedbrakes don't retract in time and you are close to the ground I don't know how much margin you would have left.