@David_H, which year/model is your Fire HD tablet? and did you sideload Google Play Store/Services on it? I am curious if the navigation performance is degraded due to the sideloading, or having too many space tiles? (You can merge multiple small space tiles into fewer bigger tiles to help with the performance.)
Changing the transition animation is not currently supported but you may want to cast your vote in the feature request below:
You might be able to do it in a wrapper page, but I think there might even be challenges with that. I don’t think you can get swipe/drag events from an iframe without putting some sort of overlay on it… and then that would prevent you from interacting with the content of an iframe.
Edit: Depending on your dashboard setup, a workaround might be to have an invisible overlay at the bottom (or top) of the screen that acts like a swipe zone. This wouldn’t be quite as intuitive to a new user, but it might work depending on your needs.