After flashing LineageOS, the only missing thing for me was the stock Camera app. The BSG GCam is very good, but it sill misses some things, namely the ability to use the LED ring around the sensor for macro photography or combined zoom using both sensors. So here follows a small report what I've managed so far on LineageOS 19 lineage-19.1-20220507-nightly-nio-signed.zip .

I got the Camera app working (so far I have not noticed any problems in any of the modes). To get this working, you need add some files to mark the phone as "compatible". You can do this using the attached Magisk module, or by using the xmlpak module. Then you should be able to install this APK extracted from an Android 11 FW dump.

At this points, you will be able to install the Play Store version, however, it will crash (not able to intitialize the camera in many modes). This also applies to the 12 version extracted from the FW.

I was not able to solve why this happens. If someone could send and adb logcat of loading the camera service and starting the camera application, that would be appreciated. I have tried applying the vendor files from Android 12, but to no avail (+two libraries could not be used due to VNSDK incompatibility).