That's what i understood with my limited scope. Video display Roadside Stations with EMD where Passenger stopped a minute. Freight were not to park long!! EMD got regenerative braking system to minimize energy loss & in Passenger video we see Notch pulled down past Starter (as High Notch managed to pull Rake with no need to replenish Reservoir afterwards)!!
You may loose more energy trying to pull Rake with Break Pad semi released and Optimum Reservoir Pressure let you quickly push Pad off wheels & avoid Red Burn Wheels/Break Pad (Guess)!!