It would give the GM or Campaign maker the option to continue with harder battles in their story, rather then having to try and re balance each campaign for leveling.
From what I know of the GM mode, it would be easy for the GM to just give enough xp to reach certain level and give money for some loots.
And I am fairly sure you can start our custom campaign by giving xx amount of XP to start with in a room with merchant selling things for your level.
If it's mainly to start at a predetermined level or with certain powers, this really doesn't feel like this is needed.