I still want to know how you can write post-E fluff...

Badly. But if you think about it, Entity's actually terribly romantic - since Jack is willing to kill Sam, he doesn't have to worry about the reasons behind the existence of the anti-frat regulations, and they can just be cute little snuggle puppies together. *shippers all round the world cheer*

Why the script writers chose not to follow that plot arc, I have no idea