Hello, how do I change the SDDM login screen in KDE-Linux (Atomic environment) if the new theme needs to be downloaded?
You can’t; KDE Linux doesn’t support SDDM theming at this time.
Is SDDM theming expected to be re-enabled in a later phase of KDE Linux (e.g., Beta or Stable)? Is there any roadmap information about this?
No. In fact SDDM is in the process of being abandoned in favor of Plasma Login, which doesn’t support arbitrary QML theming at all. What it does support is getting the widget style, colors, icons, etc from the system based on your preferences.
For some explanation of why, see # A Roadmap for a modern Plasma Login Manager – David Edmundson's Web Log
Plasma Login is shipped but not yet functional on my KDE Linux build (plasmalogin.service exists but cannot be used). When is Plasma Login expected to be feature-complete and ready to replace SDDM? Any information about the planned rollout or enabling it by default?