When it comes to incorporating the Dark Times content into the main series, I’ve actually been thinking of a fairly interesting idea involving that for a while now: Have the Dark Times content be the new Episodes 4-6, with the OT now being Episodes 7-9.
Episode 4 would be Kenobi (edited into a movie), Episode 5 would be Solo, and Episode 6 would be Rogue One. Kenobi and Solo have been swapped chronologically, but I feel like the “trilogy” is more cohesive this way: Kenobi resolves plot threads left hanging by ROTS and establishes the new state of the galaxy, Solo shows someone trying to survive in this new galaxy and establishes organized resistance movements against the Empire, and Rogue One shows these resistance movements united as a whole and leads directly into ANH.
I feel like this reorganization would have two benefits: It would allow for a bit more of a transition between the radically different aesthetics of the prequels and OT, and it would allow for the cool “trilogy of trilogies” structure to be preserved while having ROTJ be the definitive ending.
At that point just ditch the episodic trilogy structure entirely. It’s basically vestigial for what you’re doing.