I finally got around updating my 3 AppleTV 4s with the latest betas ( this may run on the current OS, but I went ahead and installed the betas, so I am not sure). This allows you to send audio from iOS to multiple AppleTVs. I tested it tonight and from what I could tell from walking from room to room, it synced the audio perfectly. You can also send different audio streams simultaneously to different rooms. I also noticed that the Apple TVs showed up in the Homekit app which most likely means that it can be added to Siri automation, but I haven’t had a chance to test that yet. I am hoping that my AirPlay devices around the house that are built into third party devices get updates, but I guess I will wait and see. Anyway, those complaining about AirPlay needing a computer to get multiroom audio (outside of the WHAALE app) should be pleased...assuming they own an AppleTV 4 or 4K.