Thanks I'm glad to hear! I am hesitant to add such a function since there are so many type of transmitters with different 2 way/3 way switches etc. My guess is that it will cause a lot of headache for people trying to set it up. It is sort of possible to do already though with a bit of workaround, you can map the keyboard shortcuts to a button/switch on your transmitter with a program such as this:
As for separate sceneries, that is a good idea, and one of the things I would like to be able to feature most of all. However, it is not possible to load custom sceneries into a Unity build, at least no way that I know of. (All the scenes have to be "baked" into the package when building the executable). I hope I will find a solution for this later on though.
Thank you for your feedback and suggestion!