Install a new font while Logos is running.
Drop down the Logos font menu. It doesn't show the new font.
All apps receive a WM_FONTCHANGE message from when any other app adds or removes a font (or whatever the equivalent is in today's Windows programming world), so Logos should have knowledge that this has happened and update their font dropdown lists accordingly. Word does it right.
http://msdn.microsoft.com/en-us/library/dd145211(v=vs.85).aspx
If you shut down Logos and restart, it refreshes its font lists. Shouldn't have to restart to get updated font dropdowns, though.