Late model Accucraft Rubies have electrically insulated wheels! I got my Ruby in January 2020 and had no idea. It is not mentioned anywhere.
I found out quite by accident. My testing and running prove that my wheels are electrically insulated.
I was steaming on our club layout while the track was energized and another club member was running his track powered train and it did not short out the system.
I put an ohm meter to the wheels to confirm the insulated wheels. Meter read infinity.
I set up a piece of track on my work bench and powered it from a bench power supply then put a DC volt meter to the rails with my Ruby on the rails and applied 16 VDC to the rails, and no short.