I didn't say it wasn't support, I said it's limited. Not to mention there are use-cases like projectors, where such a limitation is even more likely to exist.

I didn't say it wasn't support, I said it's limited. Not to mention there are use-cases like projectors, where such a limitation is even more likely to exist. It is an issue with the original hardware to rely on something it can't detect and doesn't have fallbacks for. Chromecast can absolutely change what physical outputs it offers. Say instead of talking about relying on DD+ passthrough, it lacked the support for YCbCr 4:2:2 and required RGB 8:8:8 from all displays, then that too would be something Chromecast does wrong.