I noticed something while I was generating the above images, and it was too late to fix it for now, but I noticed that the way I named certain files in my dataset was causing faces to not be learned as well. Specifically, when I would have super closeup shots of a celebrity's face, where it was just their face, I would name it something like "A closeup photo of Sydney Sweeney's face on the red carpet for a movie premiere" or whatever. However, I noticed that I never use the word "face" when generating images. So it may be learning the concept of "Sydney Sweeney's face" as a separate idea compared to "Sydney Sweeney" on its own, and because of that, some of the more detailed aspects of her face may not be learned as well when not using the word face in the generation prompt. So I did a search through all my datasets and renamed files that were named that way to just be "A closeup photo of Sydney Sweeney ..." or whoever else had photos like this. Several of the celebrities were affected by this. Some more than others. Sydney had a lot of photos like that so I see some definite impact on her facial features on some of my renders here. As I regenerate these models, they should get better at learning their faces when I post new renders from them in the future.
For now, the next model I'm working on is Elle Fanning.
EDIT: Retrained the Sydney model and I do think it's doing a better job with her face on average. So that's encouraging for the other models this impacted.