I haven’t heard about any system, but we know Mercedes lost the fired overrun system as part of the EBD ban. This offset the brake balance shift with KERS, last year it also served as the hot blown mapping for off throttle diffuser blowing.
May be the system is a new mapping solution to replicate this.
We know that Button doesn’t like imbalance in the chassis, especially at the rear, perhaps the new system isn’t working as it should.