I figured out everything about the kinks of this mod.
1. Do not use exp mod until you've completed day 3.(game prompts you to use exp item). Also, if you are just starting the game with the modded apk, set your exp multiplier to 1(having it at 0 won't allow you to gain exp at all). Have your sp multiplier to 1 as well
2. The drop multiplier applies to quest items/shop items/post battle items and items found on dungeon floors. You will corrupt your data if you attempt to pick up a GOLDEN item that's on dungeon floors and occasionally buying items from shop. Turn off mod before picking those up. Items obtained via quest(gems) will be sent to your mailbox at the quantity you placed the mod on
3. Inside a dungeon, exp mod will not work unless you have the drop mod on as well. No idea why that is.
Word of advice. Rush the common gacha to get ssr tickets while you can then save the rest of your gems for limited units.
Also, I agree with the above poster. This mod should probably be considered a candidate for vip due to the contents and the increasing popularity of this game