I like to wait about 10 seconds after the P goes dark as the car is still shutting down and plugging in as soon as the P goes dark will cause the fans to come back on.
This is another advantage of delayed charging using the Blink charger. I can plug in when the fans are running, P is lit, literally anytime after exiting the car. The fans will shut off momentarily as the Karma detects the charger connect, then come back on when the system determines that charge current is not yet available. The fans and the computers will then shut down normally.
Other than the delayed charging glitch introduced in 6.13 and fixed in 6.13.5, my Karma has never failed to charge using delayed charging with the Blink.