I've commented fuller over on Ad Astra CeJay but suffice to say, this is a great start. It promises a lot to come. It seems there are a few origins to be explored here and the interesting time jumps and players involved in it to date adds a lot of mystery. Borg interests are always bad but in a TOS setting could be lethal. The fact that Lexington crew now face going near the Romulan border just adds a further complication to the proceedings and I can't wait to see how this works/ed out. Might I also add that is cool to have a Lexington tale to boot too.
And then there is the fact that as yet we have not met the Agamemnon crew and are left wondering how it will fit into this story and why the time frames. All very interesting. I'm also looking forward to reading your new crew and seeing how they work out. Great start.