I can't find any documentation regarding the parameters for the little Z Bar scale and tick-mark on the right side of the Tool Path window. Can someone either point me at the docs or explain how that works and what it means?

I appears that the Tool Icon moving down  &  up is just whatever the total Z Axis movement is, then scaled to fit the window.

I see that the tick-mark also seems to be placed at various vertical positions against the 10 position scale but I can't figure out how that relates or what it's indicating.

Thanks for any help!

I have never really paid much attention to it but it would seem the scale is scaled to the code so the upper part will be whatever the value is for the Max Z in your code and the lower is min Z in your code.

Not sure what you are meaning by the tick mark.
Hood

In my setup there is a small horizontal red line that is overlaid on the vertical scale.

The scale is always 10 divisions as far as I have seen.

The tick-mark moves up and down depending on the z axis settings and sometimes for some z axis values it moves completely off of the screen.

I think that represents the Z Zero in Machine coords, certainly seems that way here.
Hood