It’s been a Windows standard accelerator for quite some time. It appears as the Close accelerator in the Window menu (top left icon on window caption bar) of most window objects. For a list of some of the standard accelerators …
The 1st shortcut on the above list is a solution to the Screens disappearing behind main screen issue:
... (a bit off-topic ... click to expand) ...
Interestingly, the 1st shortcut on the above list works for me to top a hidden Edit Person window … IF there is no other maximized application on the same display as RM8.
ALT+ESC switches to the next application (which for me is usually the Chrome browser on the other display.)
When I do this, the child Edit Person window pops up on top of the main RM8 window … and although it does not have focus, I can click it with the mouse to both reactivate RM8 and leave the edit window on top with focus.
So it becomes an ALT+ESC then LMB click protocol to bring a hidden edit window forward.