Both those systems have limits on what audio formats they can handle. Just how does Cloudplayer work streaming FLAC/ALAC files with them? Does the client transcode them on the fly?
We're currently working on a help page with a chart on what formats are supported and from what sources as it can get confusing.
For Chromecast, FLAC is supported. We have tested 16-bit 44kHz, 24-bit 44kHz, 24-bit 192kHz, and 24-bit 88kHz 5.1. (Please note this is for streaming only. Local playback support is limited to 16-bit 44Khz FLAC at this time.)
For Airplay. only 16-bit 44kHz FLAC is supported. We are working on adding 24-bit and 192kHz support to Airplay in a future release.