Definitely agree this story was a character piece but not entirely successful in that regard. The audience doesn't learn anything about Chapel that wasn't obvious previously.
I liked the analogy she made about McCoy being like an older brother to her. It's apt and that may be the problem with her whole character in a nutshell. Even though she's an experienced doctor and (briefly) CMO of the Enterprise, she still acts like a kid sister infatuated with her older brother's cute friend. Even in this story, despite her claims otherwise, Chapel still comes across as hung up on Spock. Throughout the novella, the lady doth protest too much that her feelings for Spock have changed.
The author does attempt to break Chapel out of her default settings by putting her in charge of the mission due to medical concerns. Unfortunately there's no dramatic tension to her decisions due to limited options and alternatives.
Spock: "We can hide or get captured."
Chapel: "I order you to hide us, Mr. Spock."
Spock: "A most logical decision, Doctor."
Obvious decisions with no surprising choices. It felt like Spock put Chapel in charge out of polite courtesy and a bit of patronization. Every choice Chapel made, Spock would have made whether she was present or not.
The author managed to wring a bit of tension out of Chapel multi-tasking and her focus being split between her ship and her patient but that only extended so far because of the characters involved. The audience already knows that Chapel, Spock and Dax are bulletproof and entirely safe. We already know the Trill secret. A little suspense came from the unknown identity of their attackers but as soon as they were revealed (Orion pirates) that suspense evaporated into a big ol' yawn.
This story ends where a better story should've began: Chapel becoming CMO of a different ship, breaking the cycles of her past and moving on with her life.