Well I am following the books for break-in. not going over 5500 rpm and not going over 110 mph. I have done a few quick accelerations. Maybe 5 or 6.
Personally if breaking it in like you stole it was all that bad and if hard break-ins were truly that bad for the car I seriously doubt BMW would trust a driver to do it considering they back the warrantee. If in fact a hard break in lead to say 5 out of 100 engine replacements compared to 1 out of 100, BMW would defiantly not allow us to break in the car. If in fact break in has a significant engine impact then I am sure BMW wouldn’t give us the privilege of giving them more work in the long run.
Reason why I run my car to the manual is because I don’t want any of the metal shavings that may/may not still be in the engine to screw anything up.
I'm pritty sure BMW flushed the system pritty good at the factory to the point where there is Very minimal metal shavings left if any at all. Would be interesting to ask the dealer to save your oil on the side so you can see what comes out for your first service. Or do it your self.