It's a cute trick but I can't imagine a worse ground plane. People say ok -- this is fine for low frequency circuits. There is no such thing as a low frequency

It's a cute trick but I can't imagine a worse ground plane. People say ok -- this is fine for low frequency circuits. There is no such thing as a low frequency circuit when there's a microcontroller present since the clock edges have frequency content well into the GHz. The only way I could imagine getting away with this is if you sacrifice a layer to the heater and put a ground plane between it and the rest of the PCB stack as a shield. Still I think it would be better to scatter resistors around the board and heat sink them to a solid ground plane. I don't know. I love basically everything Carl does but if anyone is considering this seriously they need to learn a bit about Maxwell's equations.