Just to give you a quick peek into those really tight "must-go" flights, when everything HAS to be there otherwise the flight will be stranded (nightban, airport closure time).
Plane goes to remote stand and at the time it is parked we have already finished (!) the boarding process by putting all pax into the busses. Means: we have the certainty that all checked in pax are available (missing passengers are not the problem BTW, only their luggage which has to be removed and this is the time consuming part).
Airports by the way hate this because the busses are used as "mobile lounges" and sometimes have to wait longer at the plane because something is "not ready yet". We transfer the busses (passengers) to the plane and when the last inbound pax has left the plane (and minimum cleaning (or whatever is required)) the bus doors open and the passengers board the plane (through two doors).
The "only" time you save with a remote stand is the two-door scenario. De-boarding time cut by half, Boarding time cut by half.
Send the busses early enough and you do not need to care if the remote stand is 1 mile away. If the plane is late (what it is), all passengers are at the gate to board the busses. If not, offload them and offload the bag before you even started loading the bags into the plane.
Of course, in real life, a million things can happen to void your plan.
Every aircraft type has a certain minimum turn-around time (the airlines publish their own times) and the ground staff has to "turn around" the aircraft in this time minimum. This ground time isn't very generous, usually you have to struggle hard to stick to it.
Anyways, if you are SLF, me as ground crew would always lie to you about the delay and would shorten it, because if I would tell you the truth (40 minutes), you would start shopping, drinking, leaving the gate and most probably not returned in time for the boarding. This is another way to "reduce the delay". Your plane is not a bus you hop on, hop off. We need you at the gate half an hour before departure, not 2 minutes
Hope this gives you a little insight. And this is only the tip of the iceberg...
Greets,
Alex