Diki, while we were using the Audya it worked really well, but every time we wanted to change from lead to accompaniment it involved re-programming the MIDI channels, which was impractical for a real performance situation. Perhaps the Event has a different approach?
Under the circumstances, I think that, if everything else worked great other than that one thing, I would have looked at a laptop or tablet solution to re-channel your guitars on the fly. Did you also see if there was a one button/switch solution the the guitar MIDI converter could have done?
Just out of curiosity, did you find something else that would do this on the fly? There’s some quite seriously bad things that could happen if the switch between setups isn’t quite sophisticated, hung notes, pitch bend values, controller values not resetting etc.. I think this is why most gear needs you to stop playing while it does the changeover. Suddenly changing midi channels mid playing could lead to a lot of things losing their note offs, etc.