The only thing I can add is do not help the computer by varying the accelerator position during gear changes. The computer does that perfectly well. If you insist on "helping" you are upsetting the carefully calibrated gearshifts.
I cannot prove that this help contributes to SMG pump failure but I feel that is a likely result.
Let the computer do the rpm changes both up and down. Your job is to keep a steady pressure on the accelerator. Whether that is all the way on the floor or simply moderate pressure for a moderate acceleration and moderate gear change.
So far my 2005 M3 with SMG has nary a problem.