What MAV_TYPE for a (telemetry) radio

I am developing a telemetry radio that can (but must not) parse and understand MAVLink telemetry. There will be two radios, one connected to the GCS and one the the drone.
I want the radios to properly register with the GCS and drone.

What kind of MAV_TYPE should a (telemetry) radio use when sending a heartbeat? There is a Telemetry Radio component available but no properly fitting MAV_TYPE.
Is it planned to add a MAV_TYPE for radios to the MAVLink standard?

The best match may still be MAV_TYPE_ONBOARD_CONTROLLER but it would not be correct.