Still the developpers could find ways to have different outcomes based on how long a player takes to end a quest (specialy the main ones that usually rely on the fact that the main character has a main role in a world changing event), or find a way to push the quests of the various chapters to completion before the depleting of all quests (from a narrative point of view it means to create "interludes" that justify the fact that the player can spend time in completing side quests) or made the side quest influence the main one.
