You can already wake the device up over LAN, USB, or Bluetooth. You could even have a separate device such as a PC or phone that sends the wake up signal to the steam deck if you wanted. I have other devices that work this way in my home already.
It’d be preferable to manage this all on device of course, but I assure you this is solvable where existing Steam Decks already reside, without needing to fix any low level firmwares.