MenuInventory::getSlotIndex(std::string type) searches only for first slot with type, so adding new main, body, or off slots will fail. Adding new artifact slots works because searching for bonuses is done for all items. Added example to hud_alt(Also will be usefull for future testing.)
Changing slots order will cause equipping items in wrong slots. Maybe we should not touch this part at all, because having few slots with the same type will create problems if equipping based on slot type.
Notes: