https://80.lv/articles/full-photogrammetry-guide-for-3d-artists/
Vlad claims that 100% JPGs can also be used for 16 bit textures.
My bet is that it mainly affects the texture. I can’t imagine that there would be much gain if you made sure that your 8 bit images have no artifacts and if you remove the shadows as much as possible. But that’s just a very un-scientific gut-feeling…