Can one use a foot pedal to change the sounds in the Montage (similar to the way Kurzweils do)?
Yes - if you place the performances in the order that you want into live set slots you can assign a footswitch to do this.
Utility - Settings - Midi I/O - FS Assign and set this to Live Set +
Just be aware that there is a slight delay between hitting the footswitch and when the next performance is ready to sound. If the current performance has less than 8 slots then SSS will mean that it will not cut dead when you hit the footswitch but there is perhaps a second or less before you can play the next performance.
Hope this helps
thanks!