I think there are also "form saver" browser extensions that can back up form data automatically for you in case of a failed submission/browser crash.
HN is old-school and the UI doesn't seem to a big priority. I wouldn't count on it changing much... people here like it that way.
Of course my friend YOShInOn does a lot of posting for me but even then error recovery is a bitch. There was that time HN went down and was giving everyone 500 errors and dang sent me an email mentioning that my script had tried to post something 900 times. It reminds me... I need to implement exponential backoff!
But HN has no "Unlimited Comments" plan, to upsell you to. Nor ads, that they want you to view more of. Nor feature-rich software, that they want you to buy.