I am using the tiled editor for my maps. The editor has a feature that allows for running external programs and passing through arguments (Please login to see this link.)
This means I could work on my map in tiled, then launch my game from the tiled editor. If fusion allows for passing through arguments, I could also launch my game and load the current map in Tiled. Quite useful for debugging.
A workaround is to manually edit a txt file that holds the map name, but this would be an extra step.