To summarise, here are the steps to activate openrc-user services for pipewire on kde..
1. Ensure that openrc-user-pam package is installed. This will automatically purge openrc-use package.
2. Reboot once to ensure that sddm starts with proper integration with openrc-user-pam
3. There is no need for gui runlevel for sddm, as sddm drops us in "default" user runlevel on loggin in.
4. Move the pipewire.desktop file from /etc/xdg/autostart folder to prevent two sessions of pipewire/wireplumber as follows:
prabu@homepc2 ~> doas mv /etc/xdg/autostart/pipewire.desktop ./
prabu@homepc2 ~> cat pipewire.desktop
[Desktop Entry]
Version=1.0
Name=Pipewire
Comment=Start Pipewire
Exec=/usr/libexec/pipewire-launcher
Terminal=false
Type=Application
X-KDE-autostart-phase=1
X-GNOME-HiddenUnderSystemd=true
X-systemd-skip=true
5. Add the pipewire user service to default using the command. $ rc-update -U add pipewire
6. Logout and login.
7. Test with commands $rc-status -U and $ps -eaf|grep wire
prabu@homepc2 ~
 $ rc-status -U
Runlevel: default
 pipewire                               [  started 00:03:43 (0) ]
Dynamic Runlevel: hotplugged
Dynamic Runlevel: needed/wanted
 dbus                                   [  started 00:03:43 (0) ]
 wireplumber                            [  started 00:03:41 (1) ]
Dynamic Runlevel: manual

prabu@homepc2 ~
 $ tree .config/rc/runlevels/
.config/rc/runlevels/
├── boot
├── default
│   └── pipewire -> /etc/user/init.d/pipewire
├── shutdown
└── sysinit

4 directories, 1 files