I just ordered a set of those Bafang BBS01b labels.
My BBS01 has 250 engraved on the bottom of it, but down there, behind the front wheel, it is always coated in mud and cow dung. I have to regularly drive a road which is also used by cows on their way to milking - so you can imagine what that motor looks like.
The setup is entirely legal as far as max speed, and continuous power are concerned. The throttle is disabled, but labelling is distinctly absent other than the very mucky engraving under the crank motor. Kit conversions exist in a kind of No-Man's Land as regulations go, so a fake label might help .