You might be able to add such request in the auth process during the APP installiation. It should also have the 1-click type of option for shop owners to undo all the changes.
Besides that, It would be hard to make sure that auto-edition is always correct. The liquid layout and even the structure could be very different among various themes. So, if you could 100% auto-edit all types of liquid correctly, that would be great for sure.
