Given the nature of H2 and Magento, it seems like there should be a significant performance gain?
Has anyone investigated this?
Perhaps the biggest benefit of HTTP/2 is that you really don't need JS / CSS merging anymore because of HTTP pushes and multiplexes. The reason why it's good is how browsers handle scripts: whenever there's a fatal error the rest of the file will be effectively ignored. This is a big problem when several files are merged into a single bundle: should one of the first scripts fail, the rest of (otherwise totally OK) scripts will be affected too.
We have implemented HTTP/2 as a trial for one of our projects. Below are the observations.
1. The response is compressed (Gzip) by default, no need to do it explicitly.
2. Server Push is happening with this extension. We installed this extension for Magento 2 - https://github.com/yireo/Yireo_ServerPush )
3. We observed that asynchronous calls are happening but need more observation on this to confirm.
4. Not able to push JS files which are loading through require.js ( The extension is not supporting it yet, we are trying to investigate it )