In that live scenario described above, you're effectively mixing Bank and Play mode functions. [Preset change + restart of the Harpeggiator sequences]. That's a possibility with a connected Aux Switch. For a single routing, it doesn't have to be a 3-way switch. Even a keyboard sustain pedal will work. Momentary switches work best; a latching switch will require two presses to 'cycle back'.
- Press the encoder + right footswitch to enter the System mode. Turn the encoder to AUX SW.
- Press the encoder again, and turn to FLX > TIP (for example). A routing of FS2 > TIP would also work correctly in Bank mode.
- Use the left / right footswitches to change the destination / source under encoder control (< -or- >).
- Press the encoder + right footswitch to exit the System mode.
The problem with this approach is that you'll have to hit two switches simultaneously to change the preset and restart the sequence. MIDI has other solutions. Your live band may not depend on sync to MIDI clock. A direct solution would be to use a MIDI pedalboard.
Some 'boards (Behringer FCB-1010; Roland FC-300) are capable of sending out both Program Changes and CC values when each footswitch is pressed. The Program Change will select your preset, and a Continuous Controller value (bound to FLX in the System menu) will reset the sequence, at the same time.