Hey Chris/chonger -
Yeah, I have the same experience as you - one of the first things I did was try to setup an on/off and I have seen the same limitation. I gave up on that particular struggle, since 1. I can turn it off on the pedal and 2. as you have done, I’ve set it up in the return/send, and so if that is not enabled on the hx stomp, it’s no longer in the chain. have you tried cc 28 to turn on and 70 to turn off, and cycling between those two using a pos setting?
So far I haven’t tried to do anything else except set up a preset up/down, which I got working successfully using an external 3 button aux.
I will definitely keep you posted as I play with it more. Right now at least theoretically everything is working OK besides the on / off, as I expect the program changes will work ok. I’m potentially going to try to send expression controller messages from the hx stomp to the Sy-200 using command center, and then I expect I’ll get more insight into what’s going on.
Thanks for getting in touch - good to find someone with the same setup!