You can find community-driven builds, often hosted on the XDA Forums. These versions frequently offer the latest Android features (like Android 13 or 14) but may lack the rigorous stability testing of official releases. The "Bootloader" Problem

If you have an unlocked device, LineageOS offers several advantages over the stock ZenUI:

Make sure you check the latest official installation instructions for your specific model variant.

Asus provides a decent update policy, but eventually, official support will end. LineageOS ensures your device stays current. Even if Asus stops updating Android versions for the Zenfone 9, the open-source community often backports security patches and major OS updates, effectively extending the life of your hardware by years.

If your Zenfone 9 is still on ZenUI and you are happy, keep it. But if you are itching for Android 15 (or 16 in the future) and want to squeeze every drop of performance from that Snapdragon 8+ Gen 1, back up your data and join the LineageOS community. Your future self will thank you.

Without an unlocked bootloader, you cannot flash a custom recovery or the LineageOS ROM. Unofficial Workarounds:

The Zenfone 9 (codenamed "dawng" for the Global/Americas versions and "dawk" for certain regional variants) has a dedicated developer community. Thanks to the release of official kernel source code by Asus (a move praised by developers), the custom ROM scene for this device is robust.