Way back when, when I was still a sysadmin, we would use a Sun workstation and we could just select the machine we wanted to log into from the WM at the log in screen. The WM would start the X server and connect to the remote machine and things would appear like working local. No VNC or xrdp stuff, didn’t exist yet.
Is this still possible with SDDM in some way? May not be the most secure way, but it is convenient.