Good news from Joshua, Plover's programmer. The newest update from the experimental series of Plover has been released. He says:
"The latest experimental release of Plover (version 18.104.22.168) includes a graphical user interface for viewing and editing all Plover configuration parameters. This will hopefully make Plover configuration much easier and less error prone. Aside from the known-to-be-buggy support for the Gemini TX stenotype, everything in this experimental release should work as advertised. If it doesn't, please let me know or, better yet, file a bug report directly in Launchpad."
Download it here.