discuss.kde.org
Plasma 5 Menus
A full-screen customizable launcher with application directories and krunner-like search for KDE Plasma 5. The Plasma 6 version can be found here.-- ... This is a simplified fork of Kickoff which is KDE Plasma 5 Desktop's default Application launcher. The design is minimalized without compromising on power and important features.For Plasma 6 ...
plasma-custom-desktop-menu
For me, on plasma 5.6.4, all working except favorites... Waht's your version of plasma-custom-desktop-menu ? normally 2015.09.06.18.13.58. Check with alt+D+S, Go to mouse actions and click on the info button of Custom Desktop Menu. Ans use the edit button to edit your menu.