How much notice do the ground crew take of the beacon once the engines are shutdown?, not much in my experience so a pretty pointless exercise in my opinion but its not my train set so I do as I am told.
We don't go anywhere near the beast until it's off.
Most days I won't even plug the headset in until the beacon is off as some flt crew have "misunderstood" the 'click' of a jack plug
initialising as a signal to release the brakes before the chocks are in.
The exception of course is if there is an obvious problem with the APU or GPU and an engine is kept running.
And another thing, I thought it was SOP for 'beacon on' before the a/c moves regardless.