I use Arnova's v8.1: GoogleCamera-Pixel2Mod-Arnova8G2-V8.1.apk at this page https://www.celsoazevedo.com/files/android/google-camera/dev-arnova8G2/
It works great, but it can crash when switching between camera and videorecorder.
@user1528524421984, I use the same for pictures. Do you have also problems with the sound in the video? It's a very very low volume with strange 'clicks'. That's why is use the original Google camera app for video.
Thx, indeed, I also use it as default camera. And, the default camera for video but for a different reason (TA-1043).
Hmm the volume with video is very low.. But I haven't noticed any clicking sounds.