@tshering,
For my purposes, which is to access monospace & small-caps fonts for relevant portions of the few books that need them, I don't think it offers any reduced effort over the embedded font method (
mainly because I already did a bit of coding to automate that). I don't want to hard-code font names into the css for main body text because I want to retain the Kobo 'switch-fonts-on-the-fly' feature. Also I need to be able to read the same epubs simultaneously on Kobo, Sony and Android so I don't want device-specific code in the calibre master epub.
Nevertheless, it's been an interesting exercise and I thank you for your participation
I guess a reader which combined the best features of both Kobo and Sony would be just about perfect for me.