Thanks for the advice, everyone. Maybe with a font manager, I can at least reduce the number of fonts when I'm not dealing with font specimens.
When you're implementing a font cache, please make it fairly easy for users to manually clear out the font cache. Here's a situation that often happens with me: I create a large font family but there's a metadata error in one of the members of the family. If could be a Panose ID number that was wrong, a missing bold or italic flag. This can cause the font menu to get messed up. When the font is repaired and updated, I need a way to force the application to rebuild the entire cache. With Adobe apps, I have to go deep into system folders to manually delete the cache file. Not such a big deal but it's a problem when I need to tell customers how to find their cache file which can be a different location for each version and platform. So try not to bury the cache too deep if possible and give it an obvious name.