FAST03 Airbus, mini sidestick
FAST05 Airbus, Flight Control System
FAST09 Airbus Fly by Wire performance analysis
FAST14 Airbus Advanced technology and the pilot
infrequentflyer789
they also rejected the first sidestick design after flight test (not sim, flight) and sent it back to the engineers not for a bit of tweaking but for radical design changes.
Would you show your reference for that?
According to the documentation of Airbus the system was evaluated in flight by one SS on the left and one yoke on the right. The double SS and the linkage of those was tested only in the SIM and the linkage between SS was then discarded for reasons not like you describe them.
But please read yourself.