I've tried a few friction fire methods with innumerable failures. So, very well done.
I experimented with fire saw ideas with elder, smallish bamboo, and a bit of pine beading this morning. I am impressed with the basic relative ease of getting smoke if you rub something along a thin edge. The tricky bit seems to be getting enough heat into one place with fine black powder in that place to start a coal. Also the bigger the general dimensions of your materials the more robust, allowing you to put more force (body weight) into the effort. Split 1.2cm elder is just too flimsy.
I'm thinking that get the dimensions and positions and setup ideal and lots of practice and this would not be too hard a method. Certainly the videos on YouTube don't appear too much effort, but signs of being well practiced. Just give me a dry bamboo forest and couple of weeks.............