The simplicity of design allows for making very small ones and very large ones.
The low parts count and the simplicity of the mechanism make the Rolowitz Drive highly scalable. There is no mechanical reason that drives could be built to handle the largest possible torque loads for uses such as lock gates. On the small end the limitation would be how small the components could be made. In theory at least there should be no bar to building nano-scale devices.
There is no transmission of any kind today that is practical to use on a device smaller than a lawnmower. This is not because smaller transmissions would not be useful, but because all existing transmissions are far too complex to scale down. The Rolowitz Drive breaks this barrier. Not only can it be built small, it will also, at least down to a certain level, be cheaper to build the smaller it gets. It will be completely practical and economically feasible to build, for instance, electric drills and saws that can never stall or overheat the motor when they encounter difficult to penetrate materials; they would simply gear down to produce more torque, and if the maximum available torque was insufficient to continue the cut, the transmission would shift to neutral, enabling the motor to continue to turn while the blade or bit is stuck, rather than overheating and triggering a thermal cutout.