Right now SD.h and SerialFlash.h are always included in the generated audio code. I've modified the GUI javascript to include a "headers" field in the node definitions so that they are only included if one of the matching nodes exists. I'm not very familiar with the Audio library, is there any reason I'm unaware of that this would break things? (I know they are in some of the source files as well, that's the next step assuming this approach seems valid.)