Yeah, they can be made blank, that's the way i make most of mine.I can make them without any dealer name/address or the BS mark.
I'm pretty sure its a legal obligation to the suppliers and not of the vehicle owners
I'm pretty sure all they use is the 11 digit number form the V5, no personal data is recorded or heldStrictly speaking it is illegal for them to supply plates without all the bull****, including checking V5 etc etc. Although there's bound to be a can of worms with giving out V5 details, which would have your address etc etc and GDPR.....exactly what are all these plate suppliers GDPR policies with regards this ? Most probably have none.
The whole law around plates is just nonsense, not a bit of wonder it's largely ignored.