OnePlus is sweating it hard to improve its ColorOS-flavored OxygenOS 12 UI to be more user-friendly and less buggy. The stable version of the software is already available for users of the OnePlus 9 and OnePlus 8 series. It's also available as a closed beta for the OnePlus 9RT. However, if you’re among those who prefer a clean and minimal, stock Android interface, then you’ll be happy to know that the OnePlus 9RT has now got two great options.
You can now try out an unofficial build of the Pixel Experience ROM as well as an unofficial LineageOS 19 custom ROM on your OnePlus 9RT (code-name "martini"). Both of these ROMs are based on Android 12L and offer a near-stock experience, though Pixel Experience will give you a bunch of Google Pixel-like features out of the box.
The two custom ROMs are compatible with the Chinese and Indian variants of the OnePlus 9RT. Before starting, you must ensure that the bootloader on the phone is unlocked. Since there's no TWRP build available for this device yet, you have to install the ROMs using the Fastboot interface. The developer of the ROMs, XDA Recognized Developer abhinavgupta371, has shared the work-in-progress kernel source as well, so that other developers can support this device.
For an initial release, the ROMs appear to be relatively stable. The developer says the only noticeable bug is that the touchscreen gestures are not working. If you’re interested in flashing either of these ROMs, then check out the forum links below.
OnePlus 9RT: Download unofficial Pixel Experience 12 || Download unofficial LineageOS 19
In case you’re new to the aftermarket development scene, be sure to check out our guides on how to install a custom ROM and how to pick the right GApps package. As always, make sure to take a backup of your important data beforehand.