The Enterprise episode E2 was about an alternate timeline NX-01 several generations into being a generational ship. T'Pol was the only one still alive, the ship was captained by Lorian the middle aged child of Trip and T'Pol, there were numerous Phlox descendants. They had devoted their years to saving earth from the Xindi weapon. The characters and untold story are quite gripping.
Ah, I was still thinking Warehouse 13. Didn't make the Enterprise connection.
I'm currently brainstorming another TOS book, but who knows? Maybe somewhere down the road. I have yet to an Enterprise book . . ..