Unable to send intermediary headers

Hi,

It seems that node js socket methods such as req.socket.write('hello world') , socket.destroy() or req.socket.setKeepAlive() do not work on fly.

Is this something to do with how Fly routes http requests?

Also intermediary headers are not sent to the client. This includes HTTP/1.1 102 Processing and HTTP/1.1 100 Continue etc.

My use case is to keep connections alive so that fly.io requests do not time out. If there are any other ways to send null bytes/keep alives with express to keep connections alive that is compatible with fly.io, that’d be fine.