Seems like I have 2 primary choices...
1. Change to a LL01 or LL04 0W30 which I'd do with the Castrol Edge 0W30 that
@edyvw linked and take the chance that I have no engine wtty claim and/or BMW doesn't do a forensic on the oil.
If I have a engine wtty issue I can change out to the "correct" oil if it's not a tow the car in situation
2. Leave it with 0W20 until wtty runs out.
I'd be running a lower HTHS oil than ideal. Would I minimise the chance that creates wear by not pushing on the car? Or the fact that BMW's (at least my N52 powered one) run hotter when cruising negate that?
I plan to keep this car a long time.