Just to clarify, you only want the algorithm to activate when you use the expression pedal rather than activate when the preset is recalled? If so, in order to do what you want to do, your controller would need to allow a user to program custom event ranges such that any CC value over 1 activates the pedal while also sending the CC message to control the algorithm. This might be a question better suited to a Boss ES8 forum or Facebook group. I don’t think this is possible without an external event processor such as the one made by MIDI solutions.
