Sorry, I completely didn’t read all of your comment. You’re right about resistance but then again the filament won’t need to touch the enclosing coil at a large surface. In the usual bowden tubes, you have a lot of contact surface between tube and filament but this would not need to be the case in the drying coil. In the end it would all depend on the application. I’m not interested in very high speed printing (yet) because my machines are all pretty slow :).