Could you not have changed the transmit channels of the guitars on the fly? Seems to me that would have fixed the issue.

Off the top of my head, I’m not sure I know any arranger that can live swap MIDI settings on the fly, definitely not one that can live swap while a style runs. Roland BK’s could associate different MIDI Setups with each Performance, but I think the Performance had to stop before the next MIDI Set got loaded in. This is likely a precaution to avoid getting stuck notes and controller values as the setups change. It’s a minefield trying to live patch active controllers on the fly…

There are also MIDI processing solutions that run on laptops and tablets that can do fairly complex procedures on the fly. They may have sorted your issue.

You can’t always leave it to the arranger manufacture to cover every last possible contingency that might be called for extremely rare needs. That’s going to be an enormous expense with little return as only one or two buyers would ever need it! On the whole, if my arranger can’t do something, I look to the controller for a solution, or external processing to provide it.

There’s usually a way!