pipewire locks up when starting in X-GNOME-Autostart-Phase=Initialization

The included XDG autostart desktop file sets:

X-GNOME-Autostart-Phase=Initialization

However starting pipewire this "early" results in gnome-session stalling for 2 minutes (until it hits a timeout) waiting for pipewire.

My theory is that pipewire may not be doing this:

Applications in the first 4 phases MUST signal to the session manager when they are up and running (via XSMP); the session manager won't start the next phase until every app in the current phase has indicated that it is ready.

https://wiki.gnome.org/Projects/SessionManagement/NewGnomeSession

Is there a reason why you specified the Initialization phase for starting pipewire? I can 'work around' this by setting the phase to something later, e.g. Panel, and things proceed like normal, though I don't know if pipewire might be missing some functionality or ?? from having been started in a later phase than you folks intended...