This is the email message I received from the horses mouth, the utahdmv.gov which is the issuing body of street legal plates.....
“If you vehicle is registered out of state as a street legal UTV it can be used in Utah as street legal, if it is not register as that you can only get a non resident permit for off road vehicles for off road use only.”
IOW, nonresidents cannot register their UTV for street legal plates in Utah. Looks like we all need plates from another state that issues them. Idaho and New Mexico are pretty easy and inexpensive to obtain. I already have my P1000-5 plated in Idaho so I’m good....