I would have saved this for then, but since we're talking now... Yeah, the moment that we start seeing the concept of the series start to genuinely lose steam and the seams begin to show is definitely when the split between the Excalibur and the Trident happens, taking the one crew and splitting it up, particularly taking Shelby out of the day-to-day dynamic on the Excalibur. And it does seem to all come directly as a result of that Dark Allies cliffhanger of the Excalibur exploding - once Shelby's poised to get the command that has been her drive for so long, she CAN'T go back to just being the first officer. It's the same reason that Riker's storyline in TNG effectively taps out after The Best of Both Worlds and we see him start to take a backseat, once the character's story reaches a point where it's natural that they would move on, them remaining in the same place just leads to them spinning their wheels. So I do give points for trying not to fall into that trap, but it did lead to falling into another trap of too many plates spinning at once, trying to juggle the two ships (and then exacerbated in the subsequent time jump that means that now, in addition to the two ships, there's ALSO Bravo Station).
This really is, in a great deal of ways, the effective end of the actual mission to the Thallonian sector - Si Cwan and Kalinda could have left at this point and it would have felt like a conclusion, and there's honestly something of a feeling of 'well, they HAVE to stay relevant, that's the mission' to their continued presence within the series after this. But if, as a hypothetical, the Excalibur hadn't blown up and Si Cwan and Kalinda left the ship, the next book led with the Excalibur being reassigned... It honestly feels like this would have been a fine place to leave Thallonian space behind, and in some ways, it does feel like there's some push-pull between trying to pay lip service to the original idea while still going to more wild ideas that have nothing to do with Thallonian space, and I kinda think that it would have been stronger to just send the Excalibur away from Thallonian space at this point, because... I mean, the big presence of the Redeemers don't ever really play a part again, either, which is kinda frustrating. "Ewok Sith Lords" or not (side note, back when I was a kid, a friend and I did actually write up a comedy fic that included an Ewok Sith as a comic relief villain - I just bring this up because of the amusement value), they WERE built up as a major presence and enemy in Thallonian space, but they only really appear subsequently in the No Limits anthology, which just feels like a loss to the overall tapestry.
This really is, in a great deal of ways, the effective end of the actual mission to the Thallonian sector - Si Cwan and Kalinda could have left at this point and it would have felt like a conclusion, and there's honestly something of a feeling of 'well, they HAVE to stay relevant, that's the mission' to their continued presence within the series after this. But if, as a hypothetical, the Excalibur hadn't blown up and Si Cwan and Kalinda left the ship, the next book led with the Excalibur being reassigned... It honestly feels like this would have been a fine place to leave Thallonian space behind, and in some ways, it does feel like there's some push-pull between trying to pay lip service to the original idea while still going to more wild ideas that have nothing to do with Thallonian space, and I kinda think that it would have been stronger to just send the Excalibur away from Thallonian space at this point, because... I mean, the big presence of the Redeemers don't ever really play a part again, either, which is kinda frustrating. "Ewok Sith Lords" or not (side note, back when I was a kid, a friend and I did actually write up a comedy fic that included an Ewok Sith as a comic relief villain - I just bring this up because of the amusement value), they WERE built up as a major presence and enemy in Thallonian space, but they only really appear subsequently in the No Limits anthology, which just feels like a loss to the overall tapestry.