I'm guessing this feature hasn't been implemented...(yet). However I want to know what is the best Windows font manager that works seamlessly with Directory Opus?
Also don't count on DO replacing your dishwasher...(ever).
The best for me or for you? The first is not much of use for you, the second you have to find yourself. I don't think that any font manager has problems running alongside DO.
You can already install and delete fonts using Opus (or Explorer), and you can view the fonts via thumbnails (and via the viewer pane if you are on Vista).
Just got to /fonts, assuming you have Opus set to handle it as a virtual folder (which is the default). There will then be an Install New Font item in the File menu. (You can also make an Opus button which lets you select a font file in any directory and install it into the Windows fonts list.)