[rsfern]

It sounds like the induction element cradles the wok. I don’t know about the thermal gradient thing (seems plausible) but in principle you could make a gradient in the field strength right?

I would have thought that a bigger drawback would be that you can’t get even heat input while tossing the wok, though I’m not sure how essential that is

[namibj]

The coils are light enough that you could have them under spring-pressure and lubricated against the wok, so medium tossing height won't affect heat transfer. It's just a ~1mm thick planar coil out of "Litz wire", covered by a glass plate in a normal stove top.

See https://commons.wikimedia.org/wiki/File:Induktionskochfeld_S... for what's under the plate. The center silver thing is likely a thermostat/temperature sensor. The electronics may need to be a bit less ignorant to handle a flexible coil, but tracking the tank's resonance isn't even a difficult task; a Royer/Baxandall oscillator could probably be made to work.