Thank you @xhostluv, by your idea I have tried the HALauncher on a Fire TV and this can be configured optimally as a Leanback-Launcher alternative.
Since the HALauncher is not recognized as a launcher app on a Fire TV, I modified the APK accordingly. This is now defined automatically as the default launcher of Fire OS 5 (if only the HALauncher is still available and the Amazon Launcher has been deactivated or uninstalled).
If there are multiple launchers installed (but not the Amazon Launcher), the Fire OS 5 launcher selection dialog will appear, for choosing which one you want! Alternatively, you can also choose the HALauncher via Launcher Hijack.
@Speeddymon has further adapted the HALauchner to work with LauncherHijack on a FireTV 3 and FireTV Cube.
Modified version of HALauncher for Fire TV:
HALauncher-184.108.40.206.apk - new version for FireTV 3 and FireTV Cube, thanks to @Speeddymon, newest version also here
HALauncher-220.127.116.11.apk - old version
- Recognition as Home-Launcher App on Fire TVs with Fire OS 5
- Selectable via Fire OS 5
- Also works with Launcher Hijack on Fire OS 5, 6, 7 (Launcher-Hijack-V3-3.0.apk)
- Ignore Updates (old version only)
Additional settings you need to make after installing LauncherHijack if you have FireOS 6 or higher:
- Enable ADB in the FireTV device settings
- Start adb on your PC
- Run adb shell and run the below commands:
$ pm grant com.baronkiko.launcherhijack android.permission.SYSTEM_ALERT_WINDOW
$ settings put secure enabled_accessibility_services com.baronkiko.launcherhijack/com.baronkiko.launcherhijack.AccServ