It might be that HTTP preloading can remove the need for this - by putting out preload headers for the deferred AJAX requests, meaning the HTTP/2 server will automatically push the results of those requests.
I'm not sure if something would need changing regarding HTTP caching for those requests - i.e. will a non-cachable request done early be valid for the current page render.
I'm not sure if something would need changing regarding HTTP caching for those requests - i.e. will a non-cachable request done early be valid for the current page render.