I know BMW use the term "Brake Energy Regeneration" but it's not a description I'd use because there's no attempt to convert the kinetic energy released by stopping the car. But it does disconnect the alternator unless the brakes are applied and so increase power to the wheels or reduce fuel consumption, whichever way one looks at it.
I've copied the relevant bit of their press release below:
Brake Energy Regeneration (not available in all markets)
This technology ensures that the output from the engine is converted primarily into drive power, with electricity being generated for the on-board network only when the engine is on overrun or during application of the brakes. To achieve this effect the alternator is automatically disengaged from the engine while under power. Accordingly, the power the alternator would consume in the conventional mode now remains fully available for even faster and more dynamic acceleration.
An adequate supply of electrical energy to the on-board system is nevertheless ensured at all times, since the alternator is activated again as soon as the MINI returns to overrun or the driver applies the brakes.
The Bosch press release about stop/start is on their website
here if anyone wants to explore that further.