Hi Tony, when you trim a surface, the surface itself stays the same and just a new trimming boundary is created for it.

So that's normal that after a trim the surface control points stay the same, you are seeing the control points of the "underlying surface" there that is underneath all the trimming boundaries.

There is a command called ShrinkTrimmedSrf which you can set up on a keyboard shortcut though, which will shrink down an underlying surface to the size of the trim boundary, this might do what you want, it will shrink the underlying surface down so it just hugs the boundary:
http://moi3d.com/2.0/docs/moi_command_reference10.htm#shrinktrimmedsrf

Why is it that you are concerned about the control points though?

- Michael