Rod,
I've only played with the software on my PC as I don't have a wheel that I can test it on.
Unfortunately, I don't have a clue what the RPM setting actually does, I would have thought that the "Speed Scale" options would already control the RPM. I did however notice that when you alter the RPM slider and then save the settings to disk, it overwrites the Pedelec Forward or Reverse setting in the "Data.mxf" configuration file, which then prevents the program from opening on its next use.
Deleting the "Data.mxf" file in the "C:\MeiXin" folder allows the program to work again, by creating a new (empty) "Data.mxf" file, just like it does when the software is first run after its initial installation.
I'm guessing this is a programming error that is directly related to the addition of this new RPM setting slider control, whose data source appears to have been accidentally linked to the wrong element within the data storage array that is saved in the Data.mxf file.
Alan