90% of the time creaks aren’t the bb even if it sounds like it is. In my experience.
Facing is largely unnecessary these days at least for external BBs in my opinion. Even if there’s a layer of uneven paint it depends on the bb and how it fits and is loaded. If you think about screw threaded cup types, how would a bit of paint on the shell face cause the cups to misalign if the threads are aligned okay? Makes no sense yet there are some who religiously insist every frame needs facing no matter what. And of course many lbs who are quite happy to take your money for the service.
Okay sure the cups might not screw in flush but at the torques specified they almost certainly will and just squash any excess paint if it’s that bad.
These days manufacturing processes rarely leave an uneven surface there and had to be a big screw up if the faces aren’t parallel.
Of course the threads might not be aligned but that’s an even bigger manufacturing failure.