I installed Xfce with openSUSE-Tumbleweed-NET-x86_64-Snapshot20190923-Media.iso
and it seems "YaST Manage system-wide settings" is not very visible from the
GUI.

Its not in any of the menu categories in whiskermenu and applications menu.
The settings category only have Xfce settings manager and YaST Software.

To get to "YaST Manage system-wide settings" i have to go into Xfce settings
manager and look under System.

Maybe this could be improved so its not so hidden for the user in the GUI.
Not sure how it is in other desktop environments then Xfce.