Wasn't bonded clutch friction discs supposed to be an improvement over the cork discs back in the days? I have bonded discs in all my bikes, and I cannot say that I have troubles with any of them wrt clutch action - they just work. One of my bikes had cork discs almost 30 years ago, when I first tried to ride it - they didn't free up, had to use a carpet knife and a small hammer in the end. Like glued. So I got bonded discs instead, and they have never acted up like that.
Ariel W/NG '40 "Bitzer", Triumph Thruxton '04, IZH-49 '56, Tempo Standard 150 '54.