Idea: Pinecil wood burning tip (pyrography)?

[Fred Zyphal]

I thought that the whole point behind putting a processor in a soldering iron was to monitor the energy signature and match the phase change profile of the solder?  When the solder changes from the solid phase to the liquid phase, there's no need to apply enough energy to make the tip hotter, simply maintain the temperature, that way the solder flows and the tip never gets too hot or too cold.  What's going to happen when your wood doesn't melt?