The 122.475 frequency is mainly used between the balloon and the retrieve crew and RT standards are "fairly relaxed".
Strictly speaking, a radio that is able to transmit should be issued with its own licence and be assigned to a station e.g. G-ABCD however in practice, you grab any ICOM that is charged up, velcro it to one of the the uprights, test it on the ground and away you go. The other radio is slung into whichever retrieve vehicle is being used and everyone is happy.
This is one area where not strictly applying the rules is a sensible approach.
I vaguely recall there is a frequency set aside for hangliders but I can't remember it
