In keeping with the theme of making the top bar behave like a titlebar, one should be able to drag maximized/snapped windows from any part of the top panel, even if it's being occupied by a plasmoid. Most plasmoids do not require or benefit from drag behavior. Even a full volume or playback control can be used with left click and and scrollbar, and most users don't use such things anyway. But lots of users do use tile-bars to grab windows. Linux/KDE Plasma: Kubuntu 18.10 (available in About System) KDE Plasma Version: 5.14.3 KDE Frameworks Version: 5.52.0 Qt Version: 5.11.1
sorry I am not fond of the idea... any solution for this would break the plasmoids behavior