F.Y.I.
Quote out Manual (page 17 Reference Manual): During loop playback the chord input from the keyboard is disabled and the whole keyboard can be used for performance
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It is true that one can use the whole keyboard, but it has to be mentioned that if the the LEFT voice (LOWER part) is turned on, it splits the keyboard.
No problem if you are aware of it, because then you can, if you want, also use it for your composition.
PS.
I have noticed that you can save the Looper ON-status in a register memory and use it for a SyncStart when you press Reg.Memory X. But CL OFF you have to do manually.
Or maybe a 'STOP LOOPER' could do the trick (like a STOPPAD)?