I never power the car off manually.
At home, my procedure is:
- Jump out of the car (with everything still running).
- Open the charge port
- Plug in
- Lock the car
At a rapid charger, my procedure is basically the same:
- Jump out (all running)
- Open charge port
- Plug in
- Start the charge
Then I either:
- Sit in the car (all running)
- Lock the car and wander off
OR some combination of the two: lock, come back, sit in the car, lock again and come back etc...
I repeat, I NEVER shutdown the car using the power off mode. It isn't required.