You can use the Time Div to get a fairly good range, but not all in one sweep of the tempo knob.
Anyway, this is a request I've seen a few times, and I'd not mind it myself. I'd use it e.g. for programmed ratchets in the sequencer, controlled by the mod lanes.
AFAIK, Arturia is open to feature requests on their FB page for an upcoming FW update, and they take them as support tickets as always - be sure to make your voice heard to increase the chances of seeing your favourites