Hi Steve, it doesn't really work well with highly concave holes like the ones there are good examples of what won't work.

For stuff like that you'll need to kind of reduce the area of the hole by filling in some of the star arms with other modeling techniques, until you have a somewhat more regular shaped remaining hole to fill in.

Do you have any examples of other CAD software that filled in those holes very well? I'm thinking that in the future there may be a few different modes for n-sided hole filling which use different methods.

I'm going to be traveling for the rest of the day here, so I'll be offline for a while, more comments and answers when I return.

- Michael