Only Major Cleve Saville and idg seem to know their stuff here. The 'fine tuning' of the Flight Control Laws, in this case (alternate law) the amount of aileron deflection commanded by a given sidestick deflection is determined by Flap Lever position (note: not the actual slat/flap config.)
I am somewhat astounded to see someone like clandestino who has not flown the aircraft have the confidence to a somewhat derisve post based on a few hours in a sim.
Clandestiono: the sidestick is not directly connected by cables to the ailerons, so has it not occurred to you that the ELACS still control the ailerons and you may not have full knowledge of how the ELACS have been programmed or how the stick deflection/aileron displacement ratio is altered by Flap Lever position.
Don Coyote: just because you have never heard it does not make it false. Looks like a case of don't confuse me with facts my mind is made up. I suggest you google: Dragonair A320 Incident Hong Kong 1994.
I have seen crews, in the sim, inadvertently select Flaps Full whilst attempting an Alternate-Direct law landing and can confirm that controlability is 'somewhat' impaired.
Why do we select Flaps 3 for abnormal configs (except flaps/slats 0) on the A320 - because Airbus tell us to and they have more knowledge of the way the A320 works than we do.
During dual rad alt failure the Flight Control Laws go directly to Direct Law at gear down because a radio altimeter input is required to programme flare law.
i.e Flare law is not available without rad alts.
'A little knowledge is a dangerous thing'. 'How does that system work? It works really well'.