"I was installing a Shimano CN-HG93 9 speed narrow chain which uses a reinforced connector pin with a break-off adapter extension to facilitate assembly. The length of this pin exceeds the available throw of this chain tool and it was of no value in installing the new chain."
The replaceable pin can vary in length. I bought the CT-5 a number of years ago to work on 8-speed chains and it had a "short" pin. When I moved to 10 speed narrow chains, I purchased a longer replacement pin which was designed for 10 speed. Assume that the one designed for 10 speed would also work with 9 speed.
I use this chain tool. The Amazon review sounds like user error. I generally use SRAM chains but installed a Shimano chain with a pin for a friend and I don't recall any issues.
I agree. The extra-long Shimano replacement pin can be pushed almost half way in by hand (the bullet shaped end is a smaller diameter pin just for use as a guide). If you had a terribly badly designed or too-small chain tool (like a miniature one in a multi-tool, for instance) you would have to back the tool threads all the way out and maneuver the pin into the recess where the tool comes out. It can be done though. I have never encountered a chain tool that cannot be used to install Shimano rplacement pins.