I've seen a couple of headless tuner designs which used a small knurled knob, with a Allen-style hex socket in the center. That way, you could do small amounts of fine tuning on stage with your fingers, but get out a T-handle Allen wrench when you are changing strings.
Variation on the theme: One of my favorites is the Bunker micrometer tuner. It embraces the typical knurled knob found on similar designs but with an added thumb screw on the top of the assembly which alters the tilt orientation for fine-tuning.
Riis