So recently I found a way of crashing a server while in Berezino. It seems to work for all the servers I checked (ranging from approximately 5 to 25 players).
With this ability you should be able to reset a server whenever you're finished looting etc.
To do this you simply have to shoot the petrol station circled in the picture until it explodes, then the server should crash about 5 - 10 seconds after it explodes.