Another trick with midi loopback I have found is that you can customize foot switch assignments per snapshot in a preset. There are limitations but it is workable and makes the snapshot feature even more powerful.
Limitations I have encountered:
The midi assignment type needs to be the same across each snapshot. You cannot have a MIDI CC selection in snapshot 1 and then CC toggle for snapshot 2.
LED color assignment cannot be customized across snapshot. If FS1 is yellow on snapshot 1, then it will be yellow on snapshot 2 and snapshot 3.
Footswitch naming cannot be customized across snapshots. If FS1 is set to "Boost" in snapshot 1, then it will also appear as "Boost" in snapshot 2 regardless of the midi assignment. I choose to use generic names like PARM1, PARM2, etc... or you can stack them like BST-DLY-RVB so that you know snapshot 1 is Boost, snapshot 2 is Delay and snapshot 3 is Reverb.
Certain midi assignments need to be the same or it will act up. For example, when I try to assign FS4 to toggle between snapshot and stomp mode in snapshot 1 but then try to set FS4 to go directly to snapshot 1 from snapshot 2 and 3 (using CC toggle 69/dim(0) ), it freezes up.
My current setup that is working:
Snapshot 1 (Heavy):
FS1 - Set via CC toggle to turn an overdrive block on and off
FS2 - Set via CC toggle to turn a reverb and a delay block on and off
FS3 - Set via CC toggle to turn a chorus block on and off
FS4 - Set via CC toggle to switch between snapshot mode and stomp mode
Sometimes you have to hit the foot switch 2x to get it to work
Snapshot 2 (Clean):
FS1 - Set via CC toggle as a momentary switch to change parameters on the delay block
FS2 - Set via CC toggle to change parameters on a delay and a reverb block
FS3 - Set via CC toggle to turn a chorus block on and off
FS4 - Set via CC toggle to switch between snapshot mode and stomp mode
Sometimes you have to hit the foot switch 2x to get it to work.
Snapshot 3 (Aux)
FS1 - Set via CC toggle as a momentary switch to change parameters on a tremolo block
FS2 - not in use currently
FS3 - not in use currently
FS4 - Set via CC toggle to switch between snapshot mode and stomp mode
Sometimes you have to hit the foot switch 2x to get it to work.
Hopefully in future releases, line6 will add foot switch customization per snapshot so that you don't have to work around the limitations. In the meantime, this solution works perfect for me as I don't necessarily want to add a bunch of extra midi foots witch controllers. 5 is the sweet spot for me and customization per snapshot provides a lot of flexibility.
