There isn't much to fingerprint when you cache a font or javascript library approximately forever. Of course it is a huge data leak to ever let the remote server enumerate fonts, but my ideas is attempting to accommodate the idea that interesting fonts can be used, while the only extra network traffic should be the font down load on first request.

I acknowledge that it isn't perfect. Someone who is really determined could (and will) send HTML with unique URLs for every javasscript/css/whatever, effectively making a cache useless. That takes proactive effort on their part, though, and in the meantime there is a lot of low-hanging-fruit.

For example, currently Google can track those of use that ban google-analytics at the router when we load any non-Google page that requests jquery fron Google's CDN. Limiting that to "about one" load to fill the cache would be easy and help in the short term..