Some multi-layer actions like hiding, unhiding, locking, unlocking, etc. could be streamlined by allowing to do by with a single click and swipe action: Click the first icon and swipe down until the wanted layer. This is much faster than clicking the layer/group icons individually.
As it happens, the Blender does exactly that and the idea can be tried out in action by using it. So while this feature can be considered as one of those ‘software X does this, so Krita should do’, I believe this feature could improve Krita users’ workflow and thus could be copied with pride.
Screenshot from the idea (first Blender, then Krita):
As a reminder, the current functionality does the selection and/or dragging the layers no matter where the section is made. This functionality could be retained for non-icon areas or alternatively introduce the drag -handles in the front layers.