I have Inventory Pets and this mod and a bunch of other mods in my modpack.
And I got to discover that using my anvil pet I could restore mana , with each iron nugget given I could get 30 mana , I dont think this is intentional since its makes easier to use the spells.

There's a similar exploit with the blood chest in blood magic, see #66. I've had a closer look at it and I should be able to solve this by re-routing a few durability methods. I don't know if there's a config option on inventory pets' end to blacklist items that can be repaired, if so it would give you a workaround for the time being.

Fixed in the 4.2.0 release.