I don’t really see how you could scale this up to something with speeds like a maglev train. Like @simonize said, the spinning rotors are creating drag, not only in the rotational vector but any movement vector. Obviously at slow speeds that is minimal energy loss compared to the rotation, but a several hundred mph it would be much more noticeable. The other major issue I see is the high speed flux changes are going to eventually weaken your permanent magnets.
Realistically both issues could be minimized with high temperature super conductors…but like @Boundegar eluded to, I’ve been hearing about that for +30 years.
