The way I understand linking, the Phantom and the Remote exchange or save the others Mac address. One on the gimbal and the one on the remote.
Once a Phantom and Remote are linked and the gimbal is disconnected you can still fly it, but neither video or telemetry will be received by the remote. The status light on the remote will be red, the status light on the phantom will be green. You can't re-link a Phantom and Remote without the gimbal working. All this is a fact.
The secondary Phantom also needs to be linked to the remote. When you link it, the remote will have saved the Mac from the Gimbal, the Phantom will save the Mac from the remote. That seems like it would work.
But I bet it is level above that. More like the saved link could be Phantom Mac + Remote Mac = the link key.
Anybody got any thoughts?
That's all I got give it a try.
Both Phantoms status lights will have to be green, the remote doesn't matter.
The worst that could happen, you crash them both at the same time.