I imagine the carbon content of the final steal output might still be hard to control. In which case further treatment would be required, though perhaps that co

I imagine the carbon content of the final steal output might still be hard to control. In which case further treatment would be required, though perhaps that could be done directly with the molten output from the cell (e.g. by blowing CO or O2 through the molten iron depending on whether carbon should be added or removed.