Don't confuse the "tool" with the "formulas" that go into the tool.
yatzr provides a tool, ibstummin provided a tool, WIS provides a tool (via the role ratings)
Mr Hazelwood provides formulas, and WIS provides formulas (via the defaults in the role ratings if I recall properly).
You can/should tweak the formulas to suit yourself and plug those into the "tools" that you wish to use.