Friction shifting a 9 speed cassette is difficult, and 11 speed would be very difficult. IMHO of course. I "grew up" on friction shifting but tried it on a 9 speed build a couple of years ago and it was very fussy getting a clean shift and the trimming needed to be very precise. I have seen comments by experienced friction shifters that said 9 speed wasn't all that difficult. But for someone who hasn't had a lot of time with friction shifters, I wouldn't recommend it at all for anything above 8 speed.