adding a new application file in ~/.local/share/applications with "Categories=X-XFCE;X-Xfce-Toplevel;" and then listing it ~/.config/menus/xfce-applications.menu

The issue seems to be that  ~/.config/menus/xfce-applications.menu is not honored.  If I make the change in /etc/xdg/menus/xfce-applications.menu it works as expected.  Not sure why ~/.config/menus/xfce-applications.menu is not being paid attention to.