Hey gkellum,

thanks for your response. To answer your question, yes, the H9s were configured to just listen to their respective channels. I did what you suggested though. I wanted to report my observations back. 

– when all four MIDI-equipped effects are on the same MIDI channel, there are no problems, regardless of their internal order

– when all four effects are on separate channels (1-4 in this case) and the last pedal in chain is first to receive the MIDI PC command, the second to last pedal receives the next MIDI PC command and so on, like you suggested, then it appears that the problem I posted about doesn’t appear

I can still reproduce the behavior I filmed – apparently the deciding factor here is that the last pedal needs to receive its MIDI PC command first. The Boss ES-8 is capable of sending eight different MIDI PC messages at the same time by pressing one footswitch, and prior to this I did not even know that it sends the MIDI messages in order, ie. the first MIDI message is sent first, the second MIDI message is sent after that, and so on.

So in a nutshell, the problem is solved by sending the MIDI message first to the last effect in the MIDI signal chain, but the problem persists if the order isn’t that.

Well, when the H9 receives a program change message it starts loading the indicated preset, and we have seen that when the H9 is sent multiple program change messages it can start dropping MIDI messages as it tries to load one preset, then another, then another, etc.  I don’t think we’ve ever seen this happen with just a single MIDI program change being sent to an H9 though.  I’ll ask one of our testers to see if they can replicate what you’re seeing with the latest release.  

When you set up the program changes to send on different channels, presumably you configured your H9s to just listen to their respective channels?  Does your MIDI controller give you an option to order the messages?  The safest thing to do would be to target the last pedal in the chain first on one MIDI channel, the second to last pedal in the chain next and so on.