Reporting back.
Added it to my site as I said I would above.
Works wonders! Pages loaded fast but now they are lightning fast. 
Good job man, really nice library. This is such a good idea I could it see it being part of Phoenix itself.
I will report any problems I find.
Now I to add the mix command to prerender pages to before I release to keep them updated. 
PS - My server is the smalleste instance of a Hetzner VPS, so 2 vCPU / 4GB RAM.
