"As long as you're not losing traction on your rear wheels" is the key part.

The more you brake, the more weight shifts forward, which results in less traction available to use to recapture.

People vastly overestimate how much traction is available at the rear during braking, and running out of traction at the rear typically results in the car spinning (especially in an EV with low rotational inertia with most of the weight between the axles) so regen tends to be very conservatively tuned to not cause rear lock up, thus using even less of the little traction available.