Hi Ian, sorry, that I am answering so late, but you didn't write to the list and your message in my inbox is likely to be overseen.
Have you tried a right mouse button click on the kicker and then selecting "Add" / "Add Applicaiton Button" and then selecting the menu you want to add to the kicker?
Yes, but I don't want to have just one of the predefined submenus added to the kicker. I want to fully compose my own K-Menu with an individual menu structure as I would prefer it. I was hoping that could be solved by editing an additional K-Menu, but this didn't work as I described.
There are also some settings in the "Appearance/Themes" / "Menu settings" part of the Control Centre that may help
I cannot find such a menu, neither under "Appearance/Themes" nor anywhere else. Do you mean the Menu Editor, reachable via right mouse click onto kicker and then "Configure kicker" leading to a dialog where selecting the rightmost tab shows a button "Edit K-Menu"? (BTW: My translation of menu titles are most likely not identical to the english original. I hope you'll understand me anyhow.) At best I would prefer that I could drag and drop the K-Menu items to my own menu structure. But this would be a suggestion for future KDE versions. Regards, Tom