The other day I read a question about heat induced brake fade in hydraulic disc brakes caused by too much braking on long, steep descents, which is something I have also experienced when cycling in the alps. (A quite unpleasant experience, I might add.) This made me wonder if mechanical disc brakes would suffer from the same problem. There is no fluid to start boiling, so at first thought they should be heat-fade-proof.
If so, I think an optimized disc brake system would have hydraulic activation of a short mechanical lever or wire connected to the caliper itself. This way the system would optimize modulation (by minimizing elasticity) while still being safe to brake for extended periods. I realize that even with mechanical brakes, you can't brake indefinitely, as the pads, calipers and discs would overheat at some point, but if the margin is large enough to cover most practical uses, the idea might be worth exploring.
So I'd like to hear from people with mechanical disc brakes if they have experienced heat induced fade?