I recently purchased the awesome Roland SC-D70, and was frustrated by the lack of SC Map selection on the front panel. I spent about a week researching how the midi standard works and how the Roland Sound Canvas works, and one evening to modify Tom's Midi Player to allow for the custom SC map selection. It sets the map on song start, every time a song attempts to change the map, and on Sysex events (Lazy fix for GS reset). This should work for every Sound Canvas, but setting a Map which your device does not have gives unknown results.

I'm sharing this because I got much of my information from the Vogons board, and I think there might be couple of others in here looking for this feature as well. Most of the credit for this work obviously goes to Tom Grandgent for creating the original player.