I agree lifting and coasting early will save fuel. Staying on the throttle and "late braking" will not.
I would call the lift off part of the braking phase. Im not sure if they are allowed to use the recovery without the mechanical brake or not.
To save the most fuel would be not to use the regn or mechanical brake at all. Coasting is more efficient than recovery.
If I had to guess with no data as we all are doing in this thread. I would wager that Hamilton is carrying more speed through the corner and not having to accelerate as much when leaving. Either that or they are fueling him lighter so he has less mass to deal with early in the race.