Much better now. /etc/pam.d/sddm doesn't get the pam_mount.so entries, but they are copied form xdm easily enough. /etc/pam.d/sshd gets the pam_mount.so entries as well, but mounting fails (cifs_mount failed w/return code = -13). I'll have to look into that some more. For pam_winbind to correclty work with our domain setup, I still need a customized smb.conf