Here is how I deal with it:
I save all my songs in Registrations. If I need a specific Multipad I save it as Sync Start by pressing "select & the desired Multipad" at the same time. Then save to registration. The Multipad will be blinking, so you know which one it is.
If I don't need it right away I simply turn it off at the beginning of the song.
Hope this helps
Eric