I use an old Supreme Push-Pull Tapper a lot (when I can) for threading holes, but collets for this tool are rare, hardly ever the diameter of the tap that I need to hold and Supreme is now a long gone company.
I made an adjustable tap chuck to fit my tapper starting with a reasonable quality manual tap handle and machined the handle end of it into a flange with an integral key milled into the outer end and corresponding notches were milled into the end of the tapper spindle. Then I made a nut which threads onto the tapper spindle (weird 5/8-18 threads), captures the modified tap handle and holds it onto the spindle with the key in the notches to transmit torque without slipping. This just made my tapper a lot more useful because I can hold any size tap now up to 7/16" in it. Larger threaded holes still require a tap handle but I wouldn't attempt to machine thread them anyway.
Another plan that came together well.
I also got to try my re-engineered TIG foot control for the first time and it works well and is much more controllable than the factory supplied pedal.