> - I've also seen a 4mm wide patch of rough surface running
> up to the lower center of the flattest curve.
>
> - Other times there are fairly obvious oval rings around the center
> of the flattest curve.

It's hard for me to really follow the specifics of this - if you want more help getting better results in MoI it would be a lot clearer if you could post an image with these particular areas circled.

Just in general with a simple look (and in the screenshots I posted above) I was not able to see any of the problems that you are mentioning so that makes it a bit difficult to give you very good feedback about what you should do to improve it. My best guess though is that you want to use "Divide larger than" with a setting of "All" to force more even divisions throughout your mesh.

- Michael