I’m not sure what if it should be called blacksmith since you wouldn’t make any weapons or Armor.
Instead you would be able to make things like whetstones and Armor padding that would give temporary boosts to your equipment.
I think that the effects of these items would be limited to the number of hits you deal for the whetstone and the number of hits you take for the Armor padding rather than it being a timer.
however once they have worn off there would be cooldown until you can use another.
maybe if you have a certain build you would be able to make more special items once you reach a certain point in this profession like a more magical whetstone that will give you a chance to deal some extra magic dmg or something with your weapon.