I really like using the expression pedal setting that stops the effect when the pedal is stopped rather than at toe or heel as I don't need to worry about resetting it to a specific position at the end of it's use. I find however that the effect cuts out more quickly than I'd like a lot of the time so I'd like to suggest adding a parameter that defines how long the expression pedal needs to be stopped for before the effect being controlled is bypassed.
If this is already hidden somewhere and I've missed it then I look forward to being educated 
Paul