It would be nice to have access to additional documentation. It sounds like you have a kit that uses the SC throttle body, so it is hard for me to see how going through the process to reset a stepper motor would result in a more accurate TPS configuration.
Our car runs rich as well, but I am pretty sure it is due to an incorrect table for the Rover temperature sensor.
Hopefully when the new sites are completed more information will be available.
https://www.speciali...mponents.co.uk/
Some of the documentation previously available on the old site is missing.