I found out why the premium feature wasn’t working because of the Double Validation System: the game doesn’t just check a single isPremium variable, but also verifies the receipt through ShopReceiptOwned (0x47527FC), HasValidatedShopReceipt (0x47527AC), and SyncFlagsFromReceipts (0x476710C) every time the app gets focus again (OnApplicationFocus). Maybe this can help my friend who wants to fix it.