Do you have one already to test it out?

My guess would be with the selector switch is that when it is set to mono the pedal will only listen to signal coming on the tip and sleeve of the cable, regardless of having a TRS or TS jack plugged in.

On the other hand, having to flick the switch and do the line level to instrument level startup procedure on the pedal, it’s probably not too hard to also swap the input cable if you use an insert adapter rather than a long insert cable.