[Fire TV Android Development] Skel40:
Fire OS 6.7.0.2 (Android 7.1.2) Pre-Rooted Magisk Rom with TZ (Recommended!!)

Release: 4/21/2024
Changes:

DeviceSoftwareOTA

com.amazon.tv.forcedotaupdater.v2

services.jar/odex

fosservices.jar/odex

Added:

CLH

Description: This rom is patched. All accessibility, pm disable-user are working, including,

Double press home for shortcut (enable CLH) this brings up "Recent App" (last launched app), "Recent Apps", "Running Apps", "Protected Packages" (to toggle on/off)

Hold menu button (while in CLH) for hook settings which include Double Tap (HOME): Active, Long Press (BACK), Double Press (HOME) to be set to active or inactive on an application level state for the user.

More Info about the patches on OP, I give thanks to @SweenWolf for making this possible: https://xdaforums.com/t/root-mantis-firestick-4k-custom-launcher-support-and-system-patches.4461275/

Official Magisk, change .apk to .zip, NEVER flash inside the Fire OS. Bricking will occur (recovery is limited with a blown efuse if accidently flashed stock 6.2.8.0 and higher), only flash in TWRP directly as a warning: https://github.com/topjohnwu/Magisk/releases

Not Working:

Launcher Manager 1.1.8 (CLH patches add the settings via double home press, app isn't needed)

Fire OS 6.7.0.0 (Android 7.1.2) Pre-Rooted Magisk 20.0 with TZ for the streaming fix and efuse script

Release: 11/28/2023

Magisk is necessary for patching, remove via app launch and let it reboot if not needed

Note: Before flashing 6.2.7.7-lower, always flash the stock bin of the rom before flashing the pre-rooted version. I had 6.7.0.0 installed pre-rooted, wiped all partitions in TWRP, flashed the pre-rooted 6.2.7.7/3033 and it bricked. The only way out of the brick was flashing the stock 6.2.7.7/3033 and flashing the pre-rooted rom immediately after. NEVER flash 6.2.8.0-latest stock rom. This blows the efuse and patches the unlocking shorting method.
Changes:

DeviceSoftwareOTA

com.amazon.tv.forcedotaupdater.v2

PackageInstaller

AdepFOS

build.prop

# USB Charge only function

ro.sys.usb.charging.only=no (instead of yes)

ro.build.version.number=0000000000000
Description:

OTA is patched, PackageInstaller via 3rd party app install is more clearer and easier to see now, AdepFOS is removed to get LM to work, build version number is set to this to block OTA from trying to connect, and the usb charge only function is set to "no" which might explain why the usb power itself causes the unit to reboot when connected via PC.
Development: fosservices,jar/odex/services.jar/odex patching, com.amazon.tv.oobe (for blacklisted users)

Estimated Time: N/A

Fire OS 6.2.7.3 Sky-Go Fix (Android 7.1.2) Non-Rooted with TZ patching

Release: 12/05/2023
Changes:

otacerts.zip to otacerts.zip.bak in system/etc/security

DeviceSoftwareOTA

com.amazon.tv.forcedotaupdater.v2

PackageInstaller

build.prop

ro.build.version.number=0000000000000

fosservices.jar/services.jar/odex for Sky-Go support

Bugs:

The CPU cores go too high while streaming content causing the video to play at lower qualities. Further tweaks and more modifications of the build.prop with dalvik need to be adjusted to different values.

Newer Fire TV remotes won't work with this rom. Only the old 2018 remote without the app buttons and the old Alexa remote without power and volume. Fire TV Launcher Cache does build up. Always adb shell, pm clear com.amazon.tv.launcher.
Description: Sky-Go streaming works. There's no errors when launching the app

Fire OS 6.2.7.7/3033 (Android 7.1.2) Pre-Rooted Magisk with TZ fix

Release: 12/20/2023
Changes:

DeviceSoftwareOTA

com.amazon.tv.forcedotaupdater.v2

PackageInstaller

build.prop

ro.build.version.number=0000000000000

NIMH
Bugs:

Launcher Manager won't work properly due to the older interface. It partially works with some issues launching shortcuts to settings.

Fire OS 6.7.0.3/5183 (Android 7.1.2) Pre-Rooted with TZ

Release: 4/19/2024
Changes:

DeviceSoftwareOTA

com.amazon.tv.forcedotaupdater.v2
Description: ADB is blocked in apps, Fire TV Settings, My FireTV, About refreshes the device name and account name. The features that are blocked are unknown.