has anyone used 'critical' to inline 'above the fold' css with elgg?

i found this today - some code that extracts vital css from a site and produces inline css to optimise page loading:

https://github.com/addyosmani/critical

i haven't tested it since i am too busy elsewhere and there is no obvious reference to an elgg type php app in the notes in github. if anyone has used it, i'd appreciate hearing your experience.

thanks