I'm trying to location in either Google's or Apple's documentation whether you are allowed to AB test the amount of in-game currency a user would receive from an IAP.
You can't really AB test the actual $$ price of an IAP, since the product must exist on the Google/Apple dashboard, but, within the game itself, theoretically, you could AB test how much they are shown/given.
i.e.
User A see's 100 coins for $1.99
User B see's 250 coins for $1.99
User C see's 300 coins for $1.99