I’m curious about the use case for this .
Would you care to elaborate a little on what you are trying to accomplish?
How strict should exactly the same time be interpreted? Obviously not by manually switching from one zone to another? Probably also not by having 2 remotes starting playback at the same time?
With automation using the API you should be able to come quite close, but there will alway be some delay. Perhaps you can explore the Macro.on extension?
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