There have been questions on Tesla Youtube comments like "can you charge the battery by towing it?"

The thing that amazed me was you can generate power from an induction motor. Apparently you have to have the input frequency to it higher than a frequency that would drive it. A complicated algorithm for the software IMO. A moving target in a vehicle.
I did know you can create braking torque with DC injection. Early Teslas and those with 3 motors have at least one induction (squirrel cage) motor.

But even Prius, in the NmH battery days, used regenerative braking because they had problems with the hand-over from regen+brakes to all brakes. Something I saw when I was in charge of the servicing of the trolly buses in Wellington NZ. Hysteresis, the drop-out to brakes was lower that the cut-in to regen, and releasing the brakes then re-applying caused severe consternation for the driver, in an emergency.