So, this is the state of this mod:
Multipliers for damage and defense works, you are able to go through content really fast BUT, after a certain point, you are locked out of advancing because the story mode bugs out at the beginning of chapter 5, and the loot for closing a chapter is null and the option to complete the chapter doesn't work. The "rice pot", the default mode to get passive exp and gold also gets locked on chapter 99, defeating the boss's defeat is not registered by the game, and you don't go to floor 100.
Sometimes the tower of trials bugs out, the rewards show as null, and the game crashes, but a restart fixes that, this is the only mode that seems to be able to go indefinitely, so far. But since the multipliers are quite low (damage and defense maxed at x15), you don't go very far because the enemies still overpower you.
So, my recommendation is to have two devices (or use multiple spaces in the same device) to be able to play the modded version and the Play Store version, so you can advance through normal content after the points I mentioned above, and use the mod to pass on character dungeons and tower of trials. That is what I am doing.
Also,
@Axey can we have a bigger multiplier at least for defense, so we can advance the tower of trials faster? Thanks!