New Render engine and google

Relevant or not, we have no control over it.

Just keep mentioning it to the BC team where you can.

The thing is that the browser caching and information google page speed gives is a recommendation. It is based on certain methods NOT ALL of them. The way BC are doing it currently and even better with the new system is not one that will show up on something like that. I can give you a lot of sites that rank well but fail on this because the way their caching works is not one that is picked up by pagespeed.

There are other things like if you put the same site in Australia on the US DC and then run pagespeed - It will be better because that is where it is run from.

They have and they do. Other systems and companies say similar and if you actually read the pagespeed docs etc themselves, google even tell you how this is a guide and what factors may account to false positives or false readings etc.