It's a very large teapot cosy, in other words. Seems reasonable, though obviously you still need some way to bring the pot up to temp (for that cast iron, induction would be efficient if not low-tech).
The stove with one burner dropped down [1] seems more practical, not requiring a separate device/extra step.
[1] https://krisdedecker.typepad.com/.a/6a00e0099229e8883301a3fd...
It is cleaner perhaps and more purpose-built. But I would not call that practical.