2 Independent Channels with One Expression Pedal

Is there to use and expression pedal, for example to control the volume on a GT-1000 Core and also to control the feedback on a DD-200 delay but not at the same time? I want to switch what the expression pedal does based on what page I am or by setting a switch to change between external devices.

Yes! Just set up all of your expression messages for both the core and the boss, and then in each preset that you want to use expression presets, add a ‘select Exp message’ to select the Exp presets you want AND deselect the Exp presets you don’t want.