I finally spent about 3 hours downloading various Gcam mods(most of which refuse to even load the UI, curse you Vivo) and tinkering and finally found one that runs without crashing(not any of the latest, it's in fact about 2 years old, barely newer than the one running on my Note8) and provides the processing that I had access to with my Note 8. The key is to output DNG, stick to night mode for everything, and turn off dehaze and do it yourself in LR in post, so many Gcam mods that don't even have the option to tweak dehaze are out of the question as Google's failed dehaze seems to be the culprit leading to texture destruction in recent Pixel models. Lifting shadows using the tone curve or gamma curve also helps bring out a natural look instead of crushed shadows. I've yet to see if some of the denoise parameters should be tweaked but as it is it's already better than my Note 8 because this version allows using the system default noise pattern, which vastly improves chroma noise behavior compared to the Pixel noise pattern and allows effective denoise in LR, whereas previously LR's chroma NR was almost always ineffective, either dialed to >30 for a modest effect(reducing fine noise but leaving large color blotches untouched) or having no effect at all, while now 5-10 entirely cleans up everything.
This is what progress in mobile photography should look like:
https://www.celsoazevedo.com/files/android/google-camera/dev-UltraM8/f/dl1/
Though neither of my phones can run it, it should bring out the last drop of performance from any hardware supported.