This bug is so old and tbh its a big f*** y** for KDE developement or whoever is responsible for this shitshow called SDDM. Its the reason my desktop pc is running LDM for multiple years now, since I stumbled over this.
But yeah, we need more KDE specific tools tralalala, instead of a working login manager.
Uhm both displaying copy/move process and having shortcuts for "favourite" dirs is quite possible with nnn. Although for the later I mostly use -S argument for persistent session.
The only drawback of nnn in my book is the kind of weird/cumbersome way to configure it eith ENV variables. And the non-existent preview image display under wayland.