Posted by BSG here, translated by Oleg.
* HDR+ is disabled upon the first start or if you clear cache (works like this on original google camera if used on non-google phones)
* Fit motion photo for all models (if auto-config is used) and for few configs (works on Experimental Features (Pixel), Pixel 2016 Zsl Hdr, Pixel 2017 Zsl Hdr+), when activated use_photo is enabled too (Google Photos will replace internal gallery). If you don't like that, you can disable use_photo and enable_micro in developer settings.
* Added black level offset setting for front camera (set 64 if you get purple tint)
* Tried to make it work on 7.0, might have forgotten something so I can't guarantee 100% work. There is not HDR+ on front camera for Mi5s using 7.0
* 60fps video support
* Something else? Can't remember