Sorry, what I meant was have the Engine automatically handle the conversion. That way the users can still drag-and-drop or import any audio file type, and the engine will convert it on import. That way the engine still treats it as a .wav even though you imported it in another format. I only say this because It might be easier than ensuring that all platforms the engine ships too supports that particular file-type. Most will likely support .mp3 though - I can’t see it being a problem.
The reason nobody says anything about compressed audio formats is because most people, especially developers, know sweet-FA about audio other than how to import it and hook it up. It’s often one of the most overlooked aspects of game development from design to post, something I’d like to see change in the future. I’m one of the lucky few who do since my background before this was Sound Engineering.
EDIT:
Well now… that’s interesting, I always thought MP3 was a totes-free format.