[JohnsonB]

I imagine eventually they could do away completely with calibration stickers and just use regular surface tracking with any old plywood.

[jurjenh]

But then you might want to use it with lets say glossy plain-coloured melamine sheets - most surface trackers have a lot of problems with this, so the calibration stickers are a cheap and reliable solution.

The only issue I can see is kick-back from the router bit, especially if you use larger diameter bits - this can throw the router significantly, and unless the control system compensates quickly yet gently, you may well lose tracking, leading to undefined results.

[jared314]

I wonder how a optical mouse sensor would react to the vibrations of the router.

[michaelt]

With optical mouse type tracking wouldn't you lose your position relative to other cuts if you lifted the router off the workpiece?

[BitMastro]

I imagine you can integrate information from a QR-code for global positioning and an optical mouse sensor for fine tuning