@cancelbubble – I’m halfway done on reporting this info to Browserscope. Once done, it’d be easy for a site to start contributing their user’s support data. This probably makes more sense than custom variables in google analytics..
How about caching test results somewhere (a cookie perhaps) along with useragent string and modernizr version and only run the tests if the cookie doesnt exist and/or the useragent string or modernizr version have changed?
Right off the bat running modernizr on every pageload seems wasteful – though its fairly fast.
I already gave that a shot, rasmusfl0e, but the performance gain wasn’t significant. I actually used sessionStorage, which has a big performance advantage over cookies.
Then again, I might not have done it as well as it could be..