This would make for an EXCELLENT practice tool. I’ve never found a use for a looper that has a speed change (like the QC’s 1/2 speed) when it changes the pitch.
The Digitech Jamman Stereo has a tap-tempo feature of the loop that allows you to change the speed without changing the pitch. It can get a little wonky if you try to go too slow, but within a reasonable range, it allows you practice a difficult passage slowly and eventually get it up to speed. I learned the intro sweeps to Dream Theater’s “The Glass Prison” this way on my Jamman.
Looper X is great, but this would make it truly special.