Where power x10 doesn't work at all: Arena.
Where power works but does not give rewards and stars: Outpost, Red Mountains, Tower of Trial, Event Dungeon.
Where power works and gives rewards: Goblin Mine.
I didn't try using the mod in Portal (it's PvP), Guild Battle (might end up in PvP), Devil's Ruins (I don't have summon stone atm and don't want to try it in friend's summons) and in Lab (enemy's cloner ability would make the battle endless).
In short, it's great to use the mod for farming in the Goblin Mine because we can clear all 22 stages and get all the rewards there. Also great for clearing the quest tab.
Thank you for the mod, really appreciate the work and now I can greedily farm the mine *v*)/