Seems like it would have very limited range
The ISS has flown little drones as well, but those could use fans and the ambient air for propulsion.
Rovers would be a bad choice for the lava tube, obviously, since the floor of the tube is likely just a pile of rubble from a few billion years of rock-falls.
I would kill to know the extent of contiguous open area in those tubes- on the moon and Mars.
