Hi kquiggle
I see now why you are looking at an auto clamp system, I am using a manual lathe for milling odd shapes as well as symmetrical ones hence the need for a clamp, think of my chuck as a rotary table on a mill.
For milling gears I think you may not need a clamp as the cutting forces are axial, however if you do find it desirable I would think a reasonable sized solenoid acting on a plunger in place of the screw would be enough. I am outside my knowledge base here but I am sure others will be of more help.