Censoring vanity plates is fraught with difficulties though.
Why? You just appoint some bureaucrat to do decide what is "tasteful and decent" and they do it.
My guess is the state would assert it's their license plate, not yours and you have no particular right to express yourself freely on it.
That is the argument they should make but I'm not sure it is a winning argument before a court pertaining to vanity plates.
See Mary Lewis v. Wilson, 253 F.3d 1077, 8th circuit court of appeals; Perry v. McDonald, 280 F.3d 159, 2nd circuit court of appeals; and
There is a precedent where courts found states must apply the rules equally to religious and non-religious statements of belief. In that case the license plate in question was a Christian message that was barred however so probably not popular here.
I'm on my phone so I didn't look at your cite.