I have my Viewer in view mode WINDOW.
If I press ENTER to switch to the viewer then the viewer window should be made visible i.e. Maximized if it was minimized
or brought to the top if other windows are on top of it.
When you send files to the Viewer with <Shift>+<Enter>, the Viewer window window is automatically brought into the foreground. It currently does not restore the Viewer window though.
I will add this for build 122.