The Google Camera was made to run on Pixel devices, whatever HALs, libs, permissions, etc, not in AOSP already can be extracted from the device itself (and it's not a lot, lol)
My cam works just fine, if this is the first time being on a Pixel for some of you, then you're stressing about nothing, lol, Google Camera was made for Pixels.
I can't speak for this PA build because I haven't flashed it, my builds have everything stock has, plus some. I can still use my camera to zoom @ 30x, the macro works as expected, now playing, etc, etc
There's only one way to see if a custom ROM is right for you...
That's my two pennies...