The system settings module for (multi-) screen configuration is a bit dated, and it shows a number of problems in ui that can be solved more elegantly.
I've described the current function and user interface in detail here https://community.kde.org/Solid/Projects/ScreenManagement/Design . This gives the basic understanding of what and how kscreen does its job: screen management.
The ui currently works and pretty much gets the job done, but it doesn't do so in a visually pleasing way. Some issues
* It's not immediately clear that selecting one of the outputs in the upper drag and drop area selects the output to configure in the lower section
* There's an advanced section, which only shows one setting (refresh rate)
* The ui produces scrollbars in the lower section quite often, especially when the advanced
* The drag and drop previews aren't very sexy (1)
* The wide unify output and scaling buttons at the bottom are pretty ugly
* The swindow opened for scaling setting and preview is modal, the window grows automatically, but doesn't shrink. (2)
(1) I think some kind of drag and drop system works pretty well in general, at least for me, the positioning and snapping that's currently done works pretty well. I'm open for discourse or suggestions here, of course. I think nice artwork and rethinking how they should be displayed/themed could go a long way.
(2) I think in general, this looks a bit "tacked onto it", rather than really thought through from a design and presentation perspective.
What would be needed for this task is:
* Interaction design how these tasks can be done
* Mockups that solve the above problems and look good
I'd like to implement the new design in the development cycle leading to Plasma 5.9.