MorphOS itself doesn't offer sd, but there are 3rd party tools that offer sd. I don't use it, since Amiga-m is faster and more convenient IMHO. Also the RMB on the depth gadget offers a thumbnail view of other open screens and allows simple selection.
The sd aproach with todays hw doesn't feel as smooth and natural as on the old hardware IMHO. Fancy stuff like a rotating cube for switching screens is also a nice gimmick, but not very useful.
Yeah, I never bothered with installing that screen dragging stuff on MorphOS. Frankly, it must be one of the most overly hyped and utterly useless so called "features" of Amiga, ever! Whatever real use it might have had 20 years ago, it's completely gone today. It's a gimmick at best, and quite pointless even for a gimmick. I don't want to piss on the parade here, but surely there must be better stuff to spend development time on than this?