Update: I should probably call this project ""The Neverending Tweaking" because I can't seem to stop adjusting things. I went through several versions since my last post, where I kept tweaking the face, sometimes making it worse, but eventually getting to this point. Often, I'd think everything looked great until I change camera views and saw all new flaws. Even as I started making this post, I had to go back and tweak things.
In addition to the face, re-did the hair completely, reshaped the head and neck, and finally fixed (replaced) the lapels on his blazer. I did a lot of retopology via Blender's dyntopo, which I really should have done a long time ago so I could get finer details.
I did a lot of work trying to get his head reshaped - since I began this sculpt from scratch, I've always had some problems with the basic anatomy of the head. It would look right from certain angles, but way off from others. Hopefully I've got it sorted now.
I wasn't getting the results I wanted from the hair, so I smoothed it down and retopologized before reshaping and resculpting. I kept trying different things - custom brushes, different sculpting tools - but I can never get it exactly how I want. I'll probably try some other techniques, but I think this is as close as I'll get to what I want. I think it's an improvement over v1.0, at least. I re-did the eyebrows while I was at it.
After struggling with trying to fix them, I completely remade the lapels of the blazer. The originals had some errors - too thin in sports, non-manifolds, and lacked the detail I wanted for the texture. I got a nice, crisp herrringbone pattern now, so I'm happy. Hopefully it'll print up okay. I still have some more to do with the body, but hopefully not too much. I think I'm finally down to the final details. I might try to add some skin texture to the face too, but that could be a rabbit hole I don't need to go down.