Help on using SDDM with Wayland for logging into KDE

[Archie1]

I was going through the SDDM configuration for EOS running KDE. The configuration is kept in the directory /etc/sddm.conf.d/ and it seems that SDDM uses X11. I would like to change that to use rootless-wayland. I looked at the Arch Wiki documentation related to SDDM and I have a few queries.

1. There are already two files present by default in EOS for SDDM configuration, i.e. /etc/sddm.conf.d/10-endeavouros.conf and /etc/sddm.conf.d/kde_settings.conf.
   So should I put the changes in a file like /etc/sddm.conf.d/11-EOS_KDE_Wayland.conf so that it gets processed after 10-endevouros.conf but before kde_settings.conf
   OR
   should I put it in say zz-EOS_KDE_Wayland.conf so that it is processed after both 10-endevouros.conf and kde_settings.conf ?

2. The Arch Wiki does seem to suggest that rootless wayland can be used to run SDDM, if the key-value DisplayServer=wayland or DisplayServer=wayland-user is used. Is it true? Has anyone used this?
   This key-value will probably go into the file 11-EOS_KDE_Wayland.conf or zz-EOS_KDE_Wayland.conf

3. Are there some concerns linked to using SDDM with Wayland, especially rootless wayland? Has anyone done this?

All and any inputs will be welcomed.

[galvez_65]

just add 10-wayland.conf as section 2.12.1 suggests and remove any x11 specific configs. using 10-wayland.conf as a guide you can use any Wayland Compositor you like. I personally use sway for my Wayland sddm Compositor, but thats because I want to use wayvnc otherwise kwin is likely the better option.

[nathaniel.krebs]

Just switch to Plasma Login Manager, I don’t suspect SDDM to be much longer for this world now that KDE is no longer keeping them on life support.

[Archie1]

So I figured out the solution.

Firstly there is nothing like DisplayServer=wayland-user. Rather it is DisplayServer=wayland. This has to be put in a configuration file.

Secondly the filename is important. Ideally we want to retain the EOS specific settings for SDDM, so keep the filename, which is processed after EOS specific config files. So keep the file name as zz-EOS_KDE_Wayland.conf or 999-EOS_KDE_Wayland.conf or something equivalent. The important part is the prefix zz or 999 or 99

Thirdly I have been running KDE, and plasma shell rootless now. SDDM I have not been able to run rootless. That endeavor still continues .
Though with plasma-login-manager coming into play it is doubtful how long will Arch/EOS retain SDDM. Should I be spending time on this or shift to something like LightDM or plasma-login-manager? I am still mulling on it. The aim has not changed. Run SDDM or LightDM or plasma-login-manager, i.e. the Display Manager/Login Manager rootless just like the Display Server.

Display Manager/Login Manager: SDDM, Plasma-Login-Manager, LightDM
Display Server: Wayland (Weston/Kwin) or X11/X.ORG

Thanks to @galvez_65 and @nathaniel.krebs.