Thanks for this! I have a situation that I was wondering if the app could help with. I'm using the highly unofficial community Alexa TTS app, and was hoping to use a single "proxy" device to direct output to, say, one or two of these depending on where motion is detected (and where I therefore likely am in the house). It sounded like I might be able to do this from the app description, but from actually using the app, it seems like this restriction applies to all the speakers, so I may have misunderstood the purpose. (In this case, it's because, if I'm reading correctly, people say that sending to more to about three Alexa devices at the same time causes rate-limiting problems, apparently complete TTS failure.)
Am I missing something? If not, I might try making some modifications to see if I can create a "speech director"-type thing myself to suite these needs.
Thanks!