Hi Martin,
We haven’t made any progress here yet. I have installed two test pages on my server, which are identical in content (incl. carousel). I don’t see any significant performance differences between 1.3.7 and 1.4RC2 when I pit the pages against each other.
It’s strange that a hint as “Serve images in next-gen formats” is displayed for identical images or “Serve static assets with an efficient cache policy”