I think we should fix this issue before useful middleware could be created: https://github.com/scrapinghub/splash/issues/60. Without preserving headers (including cookies) it is hard to use Splash for automation. There is no way to get headers currently.

One more thing is that interacting with the page is rough is Splash. It allows to execute javascript in page context, but it is no an easy API, and I don't know what happens if this javascript is used to redirect to an another page. Maybe @andresp99999 knows?