Works with the distance/To modifiers also, but not yet with the cabin selection (e.g. only F) - that will come but I need to rewrite the code a little. Useful for working out where you can fly from a location, when you don't know all the airport codes.
This is now fixed. The Great Circle map now observes the setting of the cabins button, so it's quite easy to determine the routes served out of (e.g.) HKG where a First class cabin is available. 0.95025 also includes updates to the flight database, plus a few other enhancements (see the change log).