

I would have it run until Kirk takes over as captain. Then jump forward to just after The Motion Picture.
This not only gives them about a decade of time before TWOK that’s barely been touched by the screen canon, they can do a design revamp to freshen the series up using TMP as a starting point, and they handle the fact that with a series per year the actors are going to quickly age ahead of their characters.
Crosspost of what I mentioned on Reddit:
Was this a sly deep cut prequel to ‘Wolf in the Fold’ ?
Given that both episodes cover the same terrain dealing with “monstrous, terrible evil” and " immortal, non-corporeal entities" possessing people?
‘Wolf In The Fold’ also ended with the entity jumping and taking over the ship.
(‘Wolf in the Fold’ in the fold was written by Robert Bloch who also wrote ‘What Are Little Girls Made Of?’, the episode that introduced Korby and Chapel)