Abstract Foreman and Weiss [Measure preserving diffeomorphisms of the torus are unclassifiable. Preprint , 2020, arXiv:1705.04414] obtained an anti-classification result for smooth ergodic diffeomorphisms, up to measure isomorphism, by using a functor $\mathcal {F}$ (see [Foreman Weiss, From odometers circular systems: global structure theorem. J. Mod. Dyn. 15 (2019), 345–423]) mapping odometer...