Version: (using Devel)
Installed from: Compiled sources
reserve unlock widgets for configuring only (not working)
Working = example: launching apps.
Ok, now you can freely do whatever you do in unlocked mode but is there any benefit of such behaviour. If the unlock mode would be only for configuring (setting size of panels, wallpaper, adding/removing plasmoids, etc.) the gain would be more efficient UI for configuring which now lives in shadow of normal operation.
Take for example changing order of plasmoids in panel -- you unlock widgets, but since you can still work / configure KDE cannot tell what your intention is. So you have to open controller for panel (extra task) and then change placement of the plasmoid. Now, note -- you opened controller not because there was some feature (within controller) but only to tell KDE "hey, I like to configure some stuff".
Such UI is not efficient because you have to do redundant task just to indicate what you are up to.
With unlock=configure only, you could unlock widgets and move panels, or plasmoids on it right away, because KDE could tell (just from unlock mode) that you are configuring KDE. No extra indication is needed. You could resize panel right away, because this what you can only do in configure mode (controller could be much more compact).
So... working in unlocking mode is possible but there is no advantage here, when reserving unlock mode to configure mode only has such advantage.
besides causing issues with kiosk settings (which could probably be worked around with sufficient amounts of special casing in the code), this has been suggested a few times already (including by the submitter) and discussed. it is not the mode of interaction we wish to see in plasma.