[bigbones]

I don't know how meaningful it is any more, but with long polling with a short timeout and a gracefully ended request (i.e. chunked encoding with an eof chunk sent rather than disconnection), the browser would always end up with one spare idle connection to the server, making subsequent HTTP requests for other parts of the UI far more likely to be snappier, even if the app has been left otherwise idle for half the day

I guess at least this trick is still meaningful where HTTP/2 or QUIC aren't in use