Amazon Kindle Fire HDX 8.9 (w/ Google Play Installed) Performance and Heating Issues

I have an Amazon Kindle Fire HDX 8.9 with Google Play installed. It's been lagging more and more recently, as well as heating up a bit more than it usually does. I've disabled as many Amazon apps as I can, uninstalled as many apps as I can, and it's still lagging more than it was a couple of months ago. I know that Android-based tablets can slow down quite a bit, but I was wondering if there are any other ways to speed up the HDX 8.9?
It's running Fire OS 5.4.0.0.

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