Rivera Chubster 40 remote control info/help wanted

TheBigDipper

I'm looking for help to integrate my Chubster 40 combo into my ES-5 switcher. It's not obvious, and I'll explain... 

You can switch channels and toggle the two boosts on/off on the Chubster using the Rivera FS7 footswitch. I have one and it works properly. One switch toggles the channel (and the LED for it), the other two turn the channel-dependent boosts (and LEDs) on/off. The connection to the amp is 8-pin DIN. It is definitely more than the equivalent of three latching switches opening or closing a circuit in the amp. There are other components inside the footswitch and - according to a diagram I've discovered - the amp sends it 18v DC down one of the pins. I'd guess that power is doing more than just lighting the LEDs, but don't really know. 

Rivera used to sell a MIDI controlled box called the FS7M. That plugs into the amp as if it were the FS7 footswitch and your MIDI controller told it what switch settings to emulate. You can still get them from Sweetwater for $250 plus shipping and UK import taxes. That's more than I think this is worth to me, so I won't be doing that. 

The Chubster is an R Series amp in the Rivera range, and I have a diagram allegedly showing what amp functions the pins on the DIN socket are connected to.

https://www.dropbox.com/scl/fi/w5ot3et9g1hvfnusb5w9u/Rivera-8-pin-DIN-wiring.jpg?rlkey=1h0knw6gzkuks5n488gvwkspj&raw=1

Asking the amp internals experts here for their thoughts - or even their actual experiences with these amps.

If I set up a latched switch to connect or break between pin 1 and pin 2, would that toggle between the channels? I don't care about the channel LED, as I'd be doing it with the ES-5 switcher pretending it's a latching footswitch. And if I tried that, am I risking frying anything inside the amp? 

I'd like to operate the boosts, too, but I suspect their switches might be momentary and use whatever circuitry is inside the FS7. Just sorting the channel switching would be 95% for me. 

I've tried asking Rivera, but most of the time they just don't acknowledge or respond to technical queries by email. As I'm actively trying to avoid buying one of their products, and they're not exactly a big operation, I can't grumble.

Anyway, help and suggestions all welcome. Ta!