I wonder if you couldn't get similar efficiencies by insulating the walls and lid of the pot itself though (and that would work on any stove, not just one that

I wonder if you couldn't get similar efficiencies by insulating the walls and lid of the pot itself though (and that would work on any stove, not just one that had a sunken burner of a fixed diameter). Choosing a good material for high-temp insulation might be tricky (without making the wall thickness high) but I for one would be happy to have an nice Ti + aerogel pan... (Ti does work on induction too!)