Even if it violates conservation of momentum, that doesn't really mean anything, since this is all happening on a quantum scale. It would definitely violate physics if you didn't need to apply a constant energy source for this to work, i.e. just one laser beam that spins in there virtually indefinitely while providing thrust. However, that is not the case.

This device presumably requires a reasonable amount of energy comparable to other existing drives. So what might happen here is a potentially unexplained quantum effect. Quantized Inertia seems like a really reasonable idea. Why wouldn't it be quantized? It doesn't even make sense for it not to be quantized.

Anyway, I hope this thing works.