I will work on adding support for this. With the current version you would just need to do a little manual editing so that this becomes S 45.5 W.

Hi, the supported units are feet, chains, poles, links, yards, sections (1 mile), vara and meters. The supported bearing format is north or south followed by degrees, minutes and seconds followed by east west. Do you encounter bearings in the format of SW followed by degree and if so where are you from? I can add support for this in the future if it is needed?