I hide the computer and use a usb touchscreen when I play live. I didn't think it would ever factor into my set but when things go wrong it gets used. Eventually an osc control surface app became part of my rig. No, nobody except Mark Rebillet wants to point and click, but touchscreens are used extensively in live music performance.
Command tracks can't be used spontaneously. I only mentioned them to point out that you are already able to skip from one part of a song to another...Your system supports this and it would be excellent if the action were linked to a click/touch at the top numbers.
I agree it would be most useful for songwriting and studio time however I also see it as a live "undo" feature. You could seamlessly back up to a few bars before with a single touch. For me personally it would be much more "honest" than using the pre-recorded track if there was a mistake. Or it could be used to spontaneously jam over a certain time range until you are ready to move on.
Thanks for adding it to the list.