As it currently stands, it’s easy for players to get an item’s durability to 0.01 lower, which is the threshold to use a repair kit.
As long as the item’s level is near or higher than the relevant craft’s level, then the xp gained is substantial even if it is at the cost of max durability loss.
Players can simply craft high level items (using +7 level enhancements to boost the level requirement) and then repair said item using basic repair kits to quickly grind xp for the crafts.
This should probably be adjusted to either the flat amount of durability repaired or the % of max durability repaired.