If you look at the A330/340 or the A320 series, you will see that the ailerons already droop down during takeoff and landing. They automatically droop down when you extend the flaps to a certain position.
Want evidence?
On the B777, the inboard ailerons droop down during landing but I think they are in the neutral position during takeoff but I am unsure of why. Engines maybe?
Feel free to correct me if I screwed up somewhere. Im no professional, Im only a fanatic with a bit of extra knowledge.
