Enable VFO definition for PTT via hamlib/rigctrld per channel

[ctand]

Usecase:

There are current production radios such as the IC-2730A that will do V/V,U/U,V/U dual concurrent receive with separate audio outputs for VFOA and VFOB. One could do 70cm PBBS + 2m APRS using direwolf with a single radio if it were possible to switch the active TX (Main/Sub) VFO to the appropriate RX channel before transmitting. Cross band PBBSs, using one radio would also be possible. The IC-2730A has CAT support in hamlib with the ability to switch the active VFO. This is all technically possible. I've verified it with the IC-2730A at least. I'm aware there will be a minute amount of additional latency in the switching of VFO's. It seems in the stereo channel mode, messages are already queued between modems sharing an audio interface. This would be similar or require similar logic at least. The audio output from direwolf would be shared on the same device but use either a stereo input or two mono input devices to independently receive the audio.

I nearly implemented this myself but I figured it wouldn't be much for someone already familiar with the codebase. I think it's mostly all there when I took a look.

Thoughts? Am I missing something that would make this a bad idea?

Best,

Chris, N6CTA