My short thought and contribution is...
UltiMaker Cura is free, I use the Lutzbot Cura version and am good with it. There's other slicing and programming software most appear to be good. e.g. PrusaSlicer, Slimplify3D and many 3D cad programs will slice and create the gcode you need with header...
Official wording in ANSI / AMSE B1.2
"NOT GO (HI) functional diameter is acceptable when the NOT GO (HI) thread plug gage applied to the product internal thread does not enter more than three complete turns. The gage should not be forced. Special requirements such as exceptionally thin or...