I had some experience with this. IME 9spd chain will work IF the cassette has no single tooth steps, ie 11->12 or 12->13. In this case the protruding
rivet will hang up on the next cog and try to shift up and fall down. IF the cassette has no single tooth jumps then it will work but may be slightly
noisier. I recently used a 9spd chain on a 10spd 11-36 cassette which has no single tooth jumps and it worked fine.