I have struck another problem with this and I meant to post about a little while back.
Whilst "Push off" has been a great addition, it does present one other issue.
If for example, I have my foot switch pressed for talkback and someone else presses..then releases the T/B button (set to Push-or) on the ARC USB, the talkback will turn off, even though I still "think" I have it activated with my foot. (other settings for the T/B don't allow it to function the way it should in conjunction with the foot switch)
This gets quite confusing if I am not watching what the other person is doing on the ARC USB.
If the ARC USB footswitch input went back to having "normally open" mode, it would all work. (as it does when I plugin a Roland piano "normally closed" footswtich --- with both the Footswitch and T/B button on the ARC USB, set to "Push-or".
Matt (PS, I think I confused myself writing this too)