Andy-
Thanks for the message and glad to hear that you are enjoying things!
Are you running the stock Fire OS? By default, apps aren’t able to unlock the screen on Fire OS devices (whereas most normal Android phones/tablets can). So the challenge is that if you automate turning the screen off, then when you turn the screen back on it will be stuck at the lock screen on a Fire Tablet.
Edit: Looking at your question again, it seems like the native screensaver and wake on motion features of WallPanel or Fully Kiosk Browser might meet your needs. No need to get into the API stuff below unless you’re looking for more advanced control or using sensors from your hub to trigger the screen.
Fully Kiosk Browser
To install Fully Kiosk Browser on a Fire Tablet, you can download it directly from the website. Just be sure to pick the version ‘for Fire OS’ from their download box:
https://www.ozerov.de/fully-kiosk-browser/#download-box
Advanced - REST API
WallPanel has a REST interface so you might be able to use that to automate turning the screen on and off:
I didn’t see an option for turning a screensaver on/off with WallPanel which is a common workaround for Fire Tablets. Another app that is popular for displaying dashboards is Fully Kiosk Browser which has a robust REST API. You can see more details about automating turning the screensaver in Fully Kiosk Browser on/off in the following thread: