MIDI would have been my favourite option but I already have an H9 that I control via MIDI. Unfortunately, my looper/switcher can only send PC messages to two devices.
You can send the MIDI going to your first H9 thru to your second H9 as well. If you don't want the 2nd H9 to do anything in a particular song, you can just save the preset associated with that program change as bypassed, and it will be loaded by the program change message as bypassed. You'd just need to rearrange the preset list of the second H9 so that it's bringing up what you need when a particular program change is received. It also has a program change receive map though too. So, you can control which preset number is loaded when a particular program change is received. Hopefully, MIDI is working on the 2nd H9…
