I have integrated 2 chromecast audios into my HA setup.
The issue I have is that I only have one input on my stereos and I always end up having to manually unplug my chromecast to plug my other input in (for example my TV) This is not idea when I want to use my chromecasts for notifications
I would either buy a separate speaker for the notifications or a amp that you can switch inputs with either IR or network commands. CC Audios are meant to be added to speakers Not sure if this really helps you tho’
I use two pi’s with HA, one for TTS mainly and the other pi for music. This is the only solution I could think of without having to switch inputs on the amp. I use two pi’s so I didn’t have to switch audio application on the pi which caused problems.
I use a switchable audio input kit and an esp8266 to do “automatic” swicthing via MQTT for inputs to my stereo.
The stereo does not have a remote, so I just switch using MQTT between CCA, squeezebox, other
It was a bit of fiddling to setup the kit, but now I have automations to switch source to CCA if it starts playing (ie a TTS), switch to squeezebox if it is playing, otherwise stay on the other channel (which is old school phono!)