Hi, James - not event-driven at this point - I have a set of tiles on the left side that (should) remain more or less constant for ease of navigation, but each of the tiles opens a different dashboard:
In the above one, Home is selected (it’s the default for this tablet), at that works fine, but when I click on “lights”, it can take 5-7+ seconds to switch to it on my Fire HD8. It’s <1s on my PC, so I am pretty sure it’s just horsepower, but thought maybe the javascript bit might help pre-load things or something. When I switch back from Lights to Home, it still takes around 5+ seconds, but I have a lot of tiles on the lights screen. I have not populated the other dashboards yet, and when I switch from Home to one of them, it’s pretty quick (around a second). I am not a developer by any means, but if there is some way I should be approaching this differently, happy to give that a try, too! 
Here is my Lights dash, for reference - these are all in-process, so missing some (or maybe a lot of) panache.
Side question: does the concept exist of a template that might have the “tabs” on the left like I have here, that can be customized with names, but that will then take whatever I put in the “home” screen left-hand nav (i.e. Home, Lights, Rooms, Basement, Security… in my example here) and populate that left-hand nav across the other dashboards? I know I can copy from one to the other, but curious to know if there was something pre-built that way, too. (I will do a search, but have not yet 
Thank you for all the help - very much appreciated!