@rog889, before jumping to the scheduled-reboot option, do you sideload Google Play store/services on those Fire tablets? I have personally experienced degraded performance over time when I sideloaded Play store/services. I have 20+ tiles and one Media tile (two live camera streams) on my 7th gen 10" Fire tablet, and I don’t have to reboot often.
If you use Blue Iris as your camera streaming source, you may want to use camera group so you can display multiple camera views in one Media Tile for better performance.
I don’t have any personal experience with it, but my quick research found “Fast Reboot” app from the Amazon App store allows you to schedule reboot or cleanup. (Not sure if the scheduling is available in the free version though.)