I've made a lot of progress on this one and I think it could be a game-changer for HD+ as well and let me explain why..
When I first started HD+ I was really excited to be learn about the 'eventstream' interface which lets the app receive 'push' updates from the Hub when any device status changes. But, this interface is only available locally and not when you're remote.
I even opened a thread 3 years ago to figure out if there was some way to access the eventstream remotely.
An possibly better alternative though would be having the Hub notify HD+ of any device updates via FCM (Google/Firebase Push Messaging).
Anyway, there's some work to do to get everything working but in the meantime I'm going to try to implement this notification / TTS feature. Later if all goes well I'll expand it to support what I originally wanted to do with pushing out device updates and removing the need to poll MakerAPI.