You could use these npc to give quests to improve the craft :
- for each craft building add a chest to stock components or resources. Its size could be increased with these quests and the size by default could depends on the level of the building.
- for each craft building add a trader who can sell component directly to players by City Traders. These sold items could come from the building chest and the number of sold items in the same time could be increased by quest
- Quests to add different type of social pets who can help the crafter to do his job : these pet can buff the player with experimentation to improve the success or decrease the craft time for example.
- Add the possibility to manage a team of npcs who can do his job offline : these npcs could do the research components against money with a possibility to improve them (better stuff, xp wih quests, guards to protec them, horses to carry more ressources and improve performance). No need to make animations or events, a simple interface monitoring will be better.