If you’re on PC, you can bypass this by editing your livery’s aircraft.cfg file. Search for the following line and add the Virgin callsign like so:
atc_airline="Virgin" ; airline name
Then when you choose the livery, make sure in your flight customisation you leave the Callsign blank. This will make the sim to read the entry above in the aircraft.cfg and use that callsign instead, which always works without going through the profanity filter.
This is how I build my own livery library. I populate all my livery collection with the proper callsign (which includes spaces and appropriate upper caps) and I just leave the flight customisation field empty all the time.
This way, I don’t need to manually change callsign every time I want to fly a different livery, as soon as I choose another livery, the sim automatically reads the callsign from the aircraft.cfg and it always works.