An easy way to mesh a spur gear and a rack is to download the step files from:
https://www.mcmaster.com/gears/
The step files don’t include the pitch circle diameter, but it’s on the product detail page or you can download a 2d file that includes the pitch circle. Gears with the same pressure angle and pitch/module will mesh correctly when the pitch circle diameters are tangent.
I found an MOI script for involute gears, but it didn’t allow for specifying the pitch/module, so wasn’t useful.
There is a Rhino plugin for gears, Rhinogears, that works well, and, it’s built from some open source code that’s available from:
https://github.com/cesarvandevelde/rhino-gears
It might be possible for someone to modify the Rhino Python code to work in MOI.
Rick