FWIW, I went through break-in twice on my E46 M3 (second one after bearing recall). I stayed within the 5500 rpm guidelines and varied the speed. But within those parameters I flogged it. That is, I accelerated hard, braked hard, and turned corners hard all before the 1200 mile break-in period. I never had problems with the engine, even before the recall. I did the recall so the warranty could be extended. But the older the engine got, the better it got. Or at least it felt that way on the old butt dyno.
I'm not recommending anyone do this. It's your call. But it worked for me.