I'm trying to manually handle the response with { selfHandleResponse: true }, but, as the doc says:

none of the webOutgoing passes are called

And that prevents me from correctly sending response.

This is the code causing the problem:

// passes/web-incoming.js
if(!res.headersSent && !options.selfHandleResponse) {
  for(var i=0; i < web_o.length; i++) {
    if(web_o[i](req, res, proxyRes, options)) { break; }
  }
}

Doing this, fixes it:

if(!res.headersSent) {
  for(var i=0; i < web_o.length; i++) {
    if(web_o[i](req, res, proxyRes, options)) { break; }
  }
}

I need to call the webOutgoing passes and do some extra stuff. But I can't.
Maybe you can expose passes/web-outgoing, or add a flag like callWebOutgoing to let users call them if they want to.