wow, that was a fast answer :-)
i find it odd that SL doesn't stop when Live stops. i haven't looked
if there is a "mute all" command
Instead of a "mute all", couldn't you just send all the SL outputs to a SubGroup inside of Live? Then, at the end, you could simply mute just that one track.
Also, I wonder if switching tracks in SL via "mute" works well with loops of different length. I guess you'd need a script like "retrigger this loop and mute all other"...?