I realize this probably means new hardware, but since there is no harm in asking… 
It would be really nice if I could configure one of the omniports to send analog expression to any non-midi pedal.
unfortunately, that requires new hardware + a dedicated port.
the tricky thing about having one port that can do everything is that there isn’t a standard. connect the omniport to a wrong port and you might fry something (most devices use 3.3v or 5v DC, but some amps use 10-12v AC). That’s why amp switching and expression out ports really need to be stand-alone, imo.