On my machine, the vertical Z axes is not what I’d call stable. It seems to me it wobbled more than the size of it’s lenses spot size, enough to visually see a misalignment, so I lock everything down to exclude backlash in the Z axes. Even the way these are mounted, they need clearance to move the head up/down… When I get energetic I’ll have to try and figure out exactly how much clearance is really there.
I also have problems nudging it, I can’t really see it with the framing led, being so bright and it’s hard to tell where it really is… especially on any kind of reflective material.
It seems to me, you’re in the same boat, anything as you still have to nudge around or scale. Compared to a jig, which should be a drop in and go operation.
Maybe I’m just getting old… 
