Thank you! It's always best to read the actual paper. I note that not only is there no shielding to reduce the Earth's magnetic field, but there are large NeF

Thank you! It's always best to read the actual paper. I note that not only is there no shielding to reduce the Earth's magnetic field, but there are large NeFeB magnets in the torsion balance assembly. I strongly suspect that the "missing momentum" is going into the object producing the magnetostatic fields which lie in the RF cavity, whether that be the Earth or the damping magnets. Not to say that this wouldn't be interesting (RF interaction with magnetostatic fields), but I don't think this has met the level of proof required of a claim of violation of momentum conservation.