To add my two cents here, as a local before getting involved with OSM, I recognized both SR XX and UT XX to refer to the same thing. Personally, I agree with the previously mentioned roadgeeks for preferring XY-123 for convenience in uniqueness, but I will concede that if UDOT is already consistent in using SR, we should switch to that.
I’ll also note that similar to the picture that mvexel shared, I’ve put similar values to ref= in name= thanks to usage on signs and addresses, such as ref=UT 117 name=Highway 117