I do not understand the ego that a "master" would have that they can stay awake for 72 hours and make reasonable decisions without mistakes.No Victor, crucible smelts can be done in portions of hours depending on the system. For wootz dendrite formation, it takes a slow cooling overnight to room temperature.
Tamahagane in the large legendary furnace runs upward of 72 hours. The master smelter stays awake the whole time likening it to helping birth a baby. Everyone helping gets to run in shifts if they have enough people.