I extended the Control4 Integration included in home assistant to also include whole home audio control. The integration will detect rooms and add them as speakers. I can turn them on and off, change the volume and even the audio source. I had to hardcode the different audio sources since I couldn’t find a way to easily find the IDs and determine which component was an audio source. Maybe if someone is interesting they can take a look to make it more extensible? But thank you Home assistant open source community for making this possible!
The repo is here: GitHub - nalin29/control4RoomMedia I also made use of a forked version of pycontrol4 and published it on pypi as pyC4Room which contains the necessary api calls to change the room variables: GitHub - kdkavanagh/pyControl4: Python 3 asyncio package for interacting with Control4 systems