John-Eric.
Thanks. No. Spin is no illusion, but so called 'quantum spin' it CAN be reprodcud from simple rotation, which YES; produces north and south poles (left/right 'curl'). BUT; OAM (in spherical rotation) is more complex than most theorists have assumed, we should include BOTH Maxwell's state momenta pairs; so LINEAR (zero curl) at the equator and CURL +1/-1 at the poles.
Correcting that allows the whole of QM to become classical (if retaining recursive uncertainty, i.e. of left/right near the poles). SR then needs the same mechanism and Einstein's 1952 ideas to unify it.
Yours is nearing the top of my list.
Very Best. Glad you're still going strong & hope you're well.
Peter