It seems development of airtime has stagnated somewhat. I have a possible unpopular suggestion. Why not offer a paid version for a reasonable price like $100 or something? Still open source. Please add the ability to add unlimited streams, though, (not just 3), and get rid of the 5 minute gap at 11:55pm, copy shows, etc., more functionality.
Development has been active, but it is currently taking place behind closed doors, but Source Fabric intends to release the code as open-source in several months last I heard. If you want to see the latest code improvements check out airtime.pro. I do agree that self-hosted airtime is desirable for a lot of people.