Implement the XDG session management protocol, in order to allow clients to ask the compositor to save window state for them. This works via creating a xdg_session_v1 object...
Stability for the end user is very good (probably even one of the best and definitely many times better than KDE) but stability for developers is not good because things often change or get deprecated which breaks the apps and the extensions they make.
I respect the gnome team for not wanting to create instability or confusion. KDE could learn a thing or two
Well GNOME does create instability and confusion too.
How so? There are lots of valid complains about gnome but stability is not one of them. They are very careful about the stuff they ship by default.
Stability for the end user is very good (probably even one of the best and definitely many times better than KDE) but stability for developers is not good because things often change or get deprecated which breaks the apps and the extensions they make.