What is the height that the laser is moving to after calibrating the zero point?

I want to do some lasering outside of uArm Studio. I was wondering how uArm Studio is handling the focusing of the Laser. Is there a fixed height it is adding to the zero point position set by the user?

Also how can I tune the focus of the laser, I have the feeling the lens is slightly out of focus, the lens seems to manually focusable to a degree (like most laser engraving heads) by turning the lens threading. Is there a special mode where it turns the laser on for only a fraction of the energy (e.g. like a laser pointer mode) for manual adjustment of the focus?