Accuracy of the FabScanPi
as it is in the kit with one laser (the one in the kit), default raspberry pi camera i measured +-100/200 microns. Depends on your build and calibration.
A laser with a sharper/thinner line, another camera module with better optics and maybe a green laser instead of a red one might bring even a better resolution. I have all the stuff lying around here, but i had not the time to give it try.
A second laser will not necessarily bring more resolution but more precise results. That is something i am working on at the moment as you can see on the pictures.