Hi Brian, yeah actually another thing you can do instead of Edit/Separate is to select the caps and delete them, leaving only the cylinder or cone surface which can then have points turned on.

Then after you have squished the points around if the end is still planar you can use Construct > Planar to recap it, it looks like you have probably already figured that out.

It's those end caps on a cylinder or cone that are trimmed surfaces, they are a larger plane that has been trimmed down to a circular outline.

- Michael