I'm the tech lead for the Flywheel proxy. The original version of Flywheel actually started with PageSpeed (with a bunch of customizations to focus on compression). You can indeed emulate Flywheel's optimizations with the appropriate configuration options for PageSpeed. We ended up rewriting Flywheel (in Go) in part because we didn't need all of the complexity that PageSpeed provides, but also to streamline the process of running the service in Google's datacenters, rather than in an Apache or NGINX environment.