I really love these new additions, but just 1 thing to "monger about"! 
These config-updates would not be necessary, if instead of having "2 switches" to turn on a feature and select if 'per game' or 'global' settings are used, I think this would be a better way, IMO:
I'm just stating my opinion. I can certainly live with 2 switches as well! I am just bringing it up, due to the force of a config-update, where it wouldn't be needed (IMO).
These config-updates would not be necessary, if instead of having "2 switches" to turn on a feature and select if 'per game' or 'global' settings are used, I think this would be a better way, IMO:
- Instead of heaving "2 switches", IMO a more appropriate way would be having "1 switch" with 3 selections (Off/Per-game/Global). --> The example is just like XYZ-Page Off/Manual/On...

- The new config-variable XYZ-Source, could be left out and rather the "Enable XYZ"-Function gets a third selection! (0=Off, 1=per-game, 2=Global) --> The result of this would be, that (1.) old configs remain compatible without an update to the config, or apps(!), (2.) Per-game-settings would still be "active" on every game, where it was already "set"(!), 3. etc.
I'm just stating my opinion. I can certainly live with 2 switches as well! I am just bringing it up, due to the force of a config-update, where it wouldn't be needed (IMO).