Controlling Boss SY-1 through CTL/EXP

I saw a similar post from last year but it didn’t quite answer my needs.
I have an MC-6 PRO on its way.

I was considering adding a Boss SY-1 to my board. Doesn’t take MIDI but does have a CTL/EXP input and the manual states this can be a foot switch or exp pedal.

With the MC6 Pro, I’m not sure if I can simply use an omniport or I have to use a relay port out (I’m guessing relay port since omniport is exp in…?)
I was contemplating a few things, not sure what’s quite possible as I’ve not worked directly with the editor yet.

I’d like to see if I could assign 1-2 buttons on MC6 to act as either a footswitch or exp pedal (I don’t want to use an external exp pedal). For instance, have one button ramp up tone/rate value on SY1, the other ramp down.

Could built in LFO engine be used to send same exp pedal messages to pedal (modulate tone/rate on pedal)?

the relay ports are for switching only. But there are devices that can convert midi to expression.

Have a look at this

Ah. How’d I miss that important point? Aright then, that plan isn’t going to work as I don’t intend to have to put another box on the board to make that happen.

Just an FYI - I’ve owned both the SY1 and currently own the SY200. I upgraded to the SY200 specifically due to the MIDI for changing presets, sweeping filters via expression over MIDI. Unfortunately Boss’ implementation of MIDI is so poor that if you sweep expression over MIDI it causes a buffer overrun and crashes the pedal. As a result I switch presets over MIDI but expression is via a direct expression pedal

That’s really good to know. Thx.