Your HomeControl concept distinguishes Entertainment Areas from physical Sonos groups. The official API documentation is the right source for which operations are actually supported, especially when synchronizing one source across multiple areas.
Why it matters: This is a concrete choice or experiment for today or this week.
Practical next move: Compare the documented group endpoints with your existing EA model before changing membership logic.
Go to Source — https://docs.sonos.com/docs/control
The Sonos Control API documents groups, players and playback operations. Action: Compare the documented group endpoints with your existing EA model before changing membership logic.