@j3s @flbr
Now that situation has a simpler solution. When you submit and the app decides you're no longer logged in: freeze! Don't touch that current tab!
Open a new tab, go to the same site, log-in. Only then move back to the tab you were typing on and go back a page.
This usually saves the text for me!
But the place where this will most likely happen to me nowadays has a surprisingly decent auto-save, so I don't really need to do this that often anymore.