I'd call or email SMS support. They answer or email back pretty quickly usually. I don't think your ML/ac will be an option since that's mixing imperial/metric. You can change the whole software between metric and other units but I've not seen where you can mix the two together. 

You can do editing/manual entries to get the rates the exact way you want. Take a look at the SMS Tutorials youtube page, I'm sure there's a how-to video or two on it. Scale data, manual entries, etc