Do you have a video on that “bed of nails” you have in there? I need to make something like that, and am digging that idea.

You cab get more distance between the probe and work pc. There is a grub on screw you can loosen and adjust to make the plunger tip travel less to close the contact . Give you more probe to material gap ! )

I can see that you have an 18mm diameter 50.8mm plano convex lens and a nozzle with a 4mm orifice. Setting the focal distance to about 19mm tells me that you are working with an ENGRAVING set up where focus is not that important. In fact best normal engraving results happen when you drop the work by 4 or 5 mm.. A CUTTING nozzle has a small (2 to 2.5mm) orifice and for efficient air assist and cutting, the gap to the work should be about 3 to 5mm max. Yes, cutting requires fairly accurate focus but dont belive what most will tell you about lenses. and focal points. The focal point of a lens is the IMAGE focal point that would work fine in a telescope, camera etc but that's not the same as the INTENSITY focal point that hapens when you shoot a laser beam through it.. In fact the nominal focal point that you think you have found can change by as much as 5mm if you change speed, power or even material. Run your focus test (maybe a ramp test?) at typical cutting speeds of about 10 to 15mm/s and then run the same test at typical engraving speed of maybe 400mm/s and you will be supprised and puzzled as to the 2mm change of focal distance.. Try the same thing with acrylic and birch plywood and you will understand that you will be continually fiddling with the autofocus pen position for CUTTING focus where the airgap is small and the risk of wiping out the pen becomes high. If youhave a production shop and run the same material and products with unskilled labour, then autofocus may have some value.. It's much more reliable and quicker to use the step gauge you have already created.

You've missed out the important bit - how do you work out what number to enter into the adjust parameter?

The autofocus feature is a disaster, causing numerous frustrations and safety risks. The faulty sensor frequently fails to adjust properly, resulting in inconsistent cuts and potential harm to the machine and materials.