If you want to get hotter and stay with electric there is a much more suitable option.
I run an insulated double boiler with a 3kW electric immersion element in the fluid bath. I say fluid bath because some time ago I ditched the water and replaced it with propylene glycol
So far I have not taken it higher than 140 degrees centigrade. That is nowhere near full power and at that temperature the glycol is not even close to boiling.
I have not experimented fully yet but how much of a temperature gradient do you wish to have?