I really can`t understand the DVLA to be honest. They sell plates knowing full well that they will be massaged to display something else.
I lived in Germany for 5 years. All plates there are supplied by the local authorities. I don`t mean the numbers, I mean the physical plates themselves.
They are all correctly spaced, with the correct font (none of those stupid italic, shadow or 3D plates) and I`m certain the Polizei would have a field day if anybody was stupid enough to try and fit anything that wasn`t supplied by the local authorities.
But, they still made money from vanity plates even though they did it legally on their terms. The guy accross the road from me had GT (indicating Gutersloh) followed by his initials RK and then 73 (the year of his birth).