I'm a fan of micro adjusters. My beef is that on miter gauges or cut of fences they are always positioned on the stop rather than near the cut. It forces you to walk back and forth, siting the cut, then walking over micro adjuster that is positioned on the other end of your work piece. Incra's rip fence is pretty cool in that often it's right next to your cut assuming you are doing a thin rip. You can click their micro adjuster while looking right down on your cut line. What I would love is if that micro adjuster could always be right next to the blade. I've thrown together a drawing of how I think it might work with some 80/20 gear, and a rack and spur gear set up, and of course JW Winco knobs.

The 80/20 forms the miter fence itself. The top extrusion slides along the bottom one using some bearings, one is a Double Keyed Linear Bearing Pad, the other is the Unibearing (by just using one side of the bearing on the back of the fence). The stop block can be macro adjusted anywhere on the extrusion, then locked in place. From there you can use the micro adjuster which turns the spur gear along the gear rack which is fixed to the mobile upper extrusion. Turn the adjuster knob, the whole top extrusion slides, which means the stop block moves with it.

Well I don't know? You only ever really need a +/- a tiny bit. Given that the the minimum length I can find some gear rack that'll fit in the extrusion is 24" I suppose it'll probably end up being 6" or so of travel? Guess I'll figure that out when I figure out how the gear rack is going to sit in the t-slot?

FWIW...McMaster Carr has some injection molded rack that they sell in 1 foot increments.

Actually, I was going to post that info a couple of days ago but I was unsure on how smoothly you wanted the rack/gear to run.

A metal rack is usually pretty smooth because it’s completely machined. Whereas, the injection molded rack, while having a nice smooth surface finish because of the molding process, the tooth geometries may be off a little bit not giving you the silky feel of a machined rack.

I’d suggest as a first round, using a plastic pinion with the plastic rack, but if that doesn’t have the feel you’re looking for, then I’d try swapping out the plastic pinion with a metal one.

Regarding the original post, fantastic illustrations but rack and pinion is the opposite of “micro” adjust. If you want to use rack then you need to replace the pinion with a screw installed parallel with the rack. A set screw with the same pitch as the rack might work but the usual approach is to forgo the rack and just use a screw in the stop block to offset the workpiece