Svarin - that is interesting. Excuse the non-AB brain here, but what are you are saying in terms of the Air Data presented to the crew at the outset? I'm afraid 'Prim 1 and 3 in Alt2 and 1 in normal' needs some translation for me. With 1 in 'normal' and the other two in 'Alt2' what would be the governing control law? Would the ASI's L and R now show a disagreement? Would they be 'invalidated'. Would the standby ASI be affected? What other baro/ADC sourced info is useable? IE Would the altimeters/VSI show the extreme climb?
Lastly, can you comment on what effect (if any) a low airspeed in the system might have on autotrim?
Apologies for all the questions, but your post is vastly more important than tailplane camber!