It is possible to set Configuration variables as Windows Environment Variables. This can be useful in some cases. They should generally be set at the User level, not System level. Use of this method is usually applicable to administrators, but may also be relevant to wider groups of users.
It is suitable for certain variables that one might wish to apply to all installed MicroStation based applications, as demonstrated in CONNECT Edition - Configuration Tips: ProjectWise Integration,
Two useful variables for administrators are
For both users and administrators, particularly when multiple products are involved, another possibility is (for very specific cases!) delivering a DGNLIB to all applications. in Using It! - Add Frequent Tools or Places to the Quick Access Toolbar I showed a couple of useful menus that I wanted to see in all my applications (they are application neutral, pointers to common tools or places).
I added a folder DGNLIB_GUI to my OneDrive for Business, then pointed MS_GUIDGNLIBLIST to it using the standard Windows environment variable OneDriveCommercial. That way I can use the same DGNLIB on any machine I log into once the Windows User Variable is added (that can be scripted on managed networks, and could point to a common network share, in my case OneDrive was more convenient).