I finally figured out the tuner issue.  Since I always play in stereo, each preset needs to be set to stereo to mute both left and right channels.  The presets that were not muting the signal were all set to Wet1/Dry2.  As soon as I changed them all to stereo, the signal was fully muted.  Is there no way to globally change all presets to stereo?

Still need to figure out the expression pedal issue.

Cheers – Tim