Works. It does not scroll the view down automatically as you drop but I don't think Kickoff did that previously either.
Verified that in unlockedDesktop=false Plasma (Kiosk) we cannot sort favorites.
(The DragHelper ungrab is so it doesn't swallow clicks like we already do in Task Manager. Will commit separately)
Video: https://www.youtube.com/watch?v=-ULgaGbnl2o