I like to call Arah storymode “Play and Pray” because you can spend over an hour in there only to be disconnected during the final fight and not be able to pick up where you were kicked out.
We’ve really needed a reconnect feature in that storymode dungeon ever since ANet turned the last PS chapter into something that could be accomplished by a single player. The downside of not having to group up is precisely this, spending an hour or more slogging through storymode, only to lose all your progress with an unfortunate disconnection.
Seriously, it’s a pain in the tukis, please consider adding a reconnect feature for solo players in the future.