It does work! Using the setup Magnus as pointed out: Broadcast message on Google Home without interrupting music and without "Incoming broadcast"
Basically, what you’re doing is creating a new routine with the same idea:
- Build a switch in HA that stores your on/off value
- Expose it to Google Home
- Build a routine that will trigger to run on the “On” state of that new on/off switch of yours.
I just tried it out to play a iHeartRadio station, and it worked!