The Steam Deck itself doesn't have an HDMI port, but the official dock does, and that does support HDMI-CEC (support was added to SteamOS a couple years ago). The Steam Deck also does support controller wake from sleep (added in the past year or so); I've actually seen people complaining about their Steam Decks waking up when they didn't realize that feature existed.
And all of the reviews I've seen about the Steam Machine talk about how well both of those features work.
The Steam Deck itself doesn't have an HDMI port, but the official dock does, and that does support HDMI-CEC (support was added to SteamOS a couple years ago). The Steam Deck also does support controller wake from sleep (added in the past year or so); I've actually seen people complaining about their Steam Decks waking up when they didn't realize that feature existed.
And all of the reviews I've seen about the Steam Machine talk about how well both of those features work.