A pre-rooted custom ROM of the latest 18.104.22.168 Fire TV software update has just been released by rbox. If you have a rooted Fire TV, head on over to the ROM download page to get your device updated to the latest stock software from Amazon without losing root. I expect to have my overview of this new update up by tomorrow, but my initial findings are that it contains only backend bug fixes and improvements over the previous version.
If you’re new to Fire TV rooting, check out my starters guide to learn how to root your Fire TV and how to use this custom ROM. As always, this ROM will not help you root a Fire TV, since your Fire TV must already be rooted to install it.