I think it would be very useful to have more options in the headphone mixing section. We already have the ability to mix different active outputs. What about adding option to mix active INPUTS as well (IN1, IN2, RET1, RET2, RET1/2 (stereo))?
Also adding option to mix the output to MONO would be very useful as well imho.
How could these features be useful:
-
Connecting different sound sources *
○ Metronome
○ Backing tracks
○ Drum machine
○ Keyboard etc. - Ability to build full IEM system without external mixing console => simpler, cleaner and cheaper rig **
- Connecting MONO only wireless system ***
* Already possible, but you need to use the input in your scene and route it to some output => you will waste a whole row on your preset grid
** 4 inputs in total has to be sufficient for you in this case. But you can expand with some micro mixer.
*** For example XVive U4 system has really good reviews but supports only MONO input. If you connect stereo source, you will hear only one channel which is of course worse than MONO.
Example - Current headphone I/O Settings
Example - Proposed feature implementation
Disclaimer: I found some similar topics but none had this specific feature. If I missed it I am sorry. And please don’t be offended by photo quality and my MS Paint skills 
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