TL;DR
Server shouldn't have to "save again" when the first player is joining from a paused game.What ?
Multiplayer servers save the map when the last player exits and pause the game (by default) - but when the player connects again, the server has to resave the map. Instead, the server should just provide the already saved map for download, as it was paused and no ticks have elapsed.This would mainly be useful on very lightly used headless servers, where only a few people are connecting.