I don´t know to do anything intuitive or sensefull with this. It´s out of tempo...
(How) can i reassign them?
Random ideas for these 2 knobs:
A metronome ( request! ) routed to the monitor out could be activated or deactivated with one of the knobs.
A classic "Hold" Funktion could hold the sound like some delay pedals have the possibility.
Switching Delay On/Off .
Switch to a second blank loop, synced to loop1 . A kind of alternate overdub.