LOL. It is all in the minds of the accountants and others who think they know it all, but know nothing.
Lets all play with seconds, of course what happens when those seconds are up, do we just shut the doors on anyone left on the platform yet to board? Do we carry the elderly who are a bit slow to get off to the next stop and hope they are quicker. What about wheelchairs, bikes, and great aunt Gerty with the wooden leg.
What about the driver who is rustling around in his bag for a snack whilst at the station? What about doors that are slow to close? Or people who insist on congregating around the doors blocking others from getting on?
You see the trouble with many posters here is this. You mean well, but the railway to you is all working timetables and what should happen. You need to add the human factor, and the problem with arguments about dwell times is the human factor has been stripped away.