The early transmissions get a little "notchy" between 2nd and 3rd due to a design error (there is a TSB), but I've NEVER heard of an M5OD being done in in this manner. I would imagine you could do a lot of damage with "power shifts." Nearly all the complaints I've seen (including the "notchiness") could be explained by incorrect fluid or oil starvation.
My own has 235K miles, and I downshift ALL the time, including with heavy deceleration (above 4000 RPM). It's an essential and very frequently used skill for mountain drivers.
I guess a lot of people don't shift very well. Further evidence is complaints of clutch lifetime. Mine always seem to last around 150K miles.