Is it possible that instead of proposing me to change my user name, the SUL system proposes me to "transfer" my A contributions to another acount (there I would specify B) and then to SUL-merge my account B ? I'm pretty sure this is technically possible, but is it something you "could plan" or "have the right" to do ? (please :-) )
My gut feeling is that merging the contributions of accounts would cause the sky to fall, but I can't actually think of anything that would go wrong... I look forward to more informed responses...