Looking for FCGear workbench explanation of parameters

[LHC]

I'm lost trying to figure out some of the parameters and what they mean. For example, when I set a simple one - "Clearance" to 0 - it looks to alter the tooth root circle diameter - but even with 0, a second gear's tooth tip does not bottom out in the gear when the gears are spaced properly. There's a measurable distance. On top of that, the clearance value seems to have no relation to the units when I'm measuring with the manipulator workbench. Backlash settings are even more obscure !

I've been digging around and looked into the wiki but I can't seem to find proper descriptions of the parameters.

Thanks for any help !

EDIT - A bit more fiddling and trying numbers in the parameters, and I might have one thing figured out.
1) With the head value altered - The amount entered into the head value parameter multiplied by the module, results in the amount of additional length (height) of the tooth.

2) I think this is the same with the clearance value. The number entered into the parameter for the clearance value, multiplied by the module, yields the amount the clearance between tooth tip/mating gear root is increased.

Wish I knew Python, maybe a scan of the code would give me the results - but opening up the code only resulted in one thing - confirmation of the fact that I don't know Python

I also came across another wiki page that I did not see when I went into the github page for the FCGears workbench and that helped with the explanation of the parameters a bit - https://wiki.freecadweb.org/FCGear_Workbench

I have no clue why I did not find this until now.

Investigations continue .......