you could make your own I guess with a set of those rollwaway car dollies and some fabbing, make two since you have two dollies in the set, go halves with a mate
My brother has something similar (and big heavy bikes like Gold Wing and a Beemer - yeah, I know, he's an embarrassment ), he uses it mainly to turn the bike around in limited space - ride in, spin around, ride out. It works well. This might be and even better set up.
I don't think I need it for the MXers and LC,
"A motorcycle is a bicycle with a pandemonium attachment and is designed for the especial use of mechanical geniuses, daredevils and lunatics." - George Fitch Atlanta Constitution, 1916