It does look like kbuildsycoca --noincremental is the key. It did not remove the listing from the test user because they were available via the central .desktop files.

On a hunch, I then ran it against one of the users who did not have the listing despite the proper entries in profilerc and the central .desktop files and, lo and behold, the options appeared.

I do a little more testing and, if it holds up, we can mark this one solved. Thanks - John