Why be interested in a he*archate rebellion?

[stormglass]

An excellent question.

1. It currently seems the most viable route to learn more about the rifts, which Xiulan would see as instrumental for ever possibly making it back to her own universe.
2. Leaping about time throughout the he*archate and interacting with other people doing likewise is a way to learn about the technology within this universe, particularly weapons tech, and see if any of it is transferable and leveragable against the centerward creature threat.  That said, the calendrical considerations and remembrances are a horror show she doesn't think Luna Command needs to know anything about, so she's most interested in things not calenderically dependent.
3. A memory: talking with Thomas McClennon not long after they had left The Broken Wings that last time, headed for Three Sky and the end of a long mission.  The revelation of the centerward threat was fresh as a blood-red bruise, as Tommy had spoken of fears conjured by the idea of generation after generation being funneled to what was needed to deal with that threat, becoming a society of warfare and quashed diversity.  Of losing their very humanity in an effort to survive.  It isn't quite the same, here, but she sees the shadows of such a thing where she looks.  At the time, it had been such a strange conversation.  Now... (Now, would she admit even to herself, that the ghost of those words may chase her?)

1 and 2 imply the thought that getting back to her home universe is feasible to her.  She may not actually believe it so.  But you keep going how you can.  You focus on the mission.

Even if you have to make up your own.