Angstrom systemd-gnome-image was very slow at the first boot.
I indeed remove the post installation process script from rcS.d/S98postinst
then the first boot to console is fast.
then manually run opkg-cl configure at command line.
it takes half an hours or more, you can use gdm to start gnome desktop windows.
angstrom first boot configuration needs to be modified somehow.
Cheers,
Dan