How to Open a Unified Font Object?

Exporting a Unified Font Object (UFO) from the File menu is self-explanatory, but I could find no topic in help.

How does one open a Unified Font Object to create a new font project?

Just browse to the UFO folder and select a file with the .plist extension.
OpenUFO.png

Weird. It seems to make no difference which *.list file I open. I can even open all four at once, but that blanks out the toolbar while the other are loading. The help file needs a few paragraphs here.
Blank Toolbars.png

You are effectively opening the same UFO font four times…