Energy recovery is energy recovery.
All Regen 1, 2, 3 and One Pedal Driving change is the amount of regen you get for a given position of the accelerator pedal.
The % pwr line on the right shows you how much energy is going out of (green) or into (blue) the battery.
Lifting off the accelerator pedal completely with the different regen levels gives you
L1 -5% regen
L2 -15% regen
L3 -21% regen
OPD -25% regen and the car will come to a complete stop
Using L1, if you take your foot off the accelerator completely, the car rolls for ages, slowing down gently. For the same behaviour in OPD you have to keep your foot on the accelerator.
Different people prefer different behaviours, but either way, -5% regen is -5% regen.
I drive everywhere with OPD and use my right foot to adjust how much regen I want. It is counter intuitive at first, but I like being able to get the car to come to a complete stop with one pedal.
Adaptive Cruise Control does use regen to slow down, but will use the brakes if it needs to. You can see what it's doing by watching the % pwr line.
I think that ACC on the 1st generation MG5 only used the brakes to slow down, but the long range version I had did use regen.