Having to refuel the steel crucible or risk losing progress towards making the steel sucks, it's not fun and doesn't respect the player's time. Everything else in the game you can bake/cook overnight and not worry about having to logging in at an odd hour to make sure you don't lose progress. Ore smelters, kilns, and the cauldron you can all fill up and forget about it. Even ovens you can load up with just 4 sticks and not worry about burning your food.
I'd much rather have steel take twice as long to cook and not need to refuel it, than the current system as is.