Move beyond the simple good and evil dynamic.
Follow the quality writing of, for example, GRR Martin’s Thrones books and have complex motivations for all characters. Actually do “There are heroes on both sides.”
Use shades of grey for characters.
The idea OF the Vong is good. An antagonist that does not care about the black and white dichotomy of Sith and Jedi. It doesn’t mean they stop being philosophical opposites, it just means that complex solutions may require complex answers and not just stabbing people.
If I had to specifically work with Disney’s sequel resources…
Rey = Grey Jedi who doesn’t embrace either side. Start off Jedi, move to Sith to counter the aggressive antagonists, end up as grey.
Finn = Instigates Stormtrooper rebellion, showing the troopers are people underneath the helmets. Start as a bit of a coward, become a leader of freedom.
Kylo = Unstable but powerful, a required compromise for the protagonists to work with against the bigger threat. Forced to curb his own destructive impulses for the greater good. Perhaps ending with a seeming death but instead in exile, left alone by the heroes just in case his expertise is ever needed for another threat 40 years later.
The point is to have character development where they end up learning and becoming different from their experiences. The war itself is, in a way, the less-important background for the characters to grow in this medium.
A three way love triangle between them would also work, as it would be character conflict and motivation. Viewers would empathize with, say, Finn having to clench his teeth and work alongside Kylo, who he hates both for political reasons AND for personal reasons with his jealousy over Rey. It would also be a good thematic mirror for the lowkey love triangle of Han/Luke/Leia (sister retcon notwithstanding) that gave Han and Luke’s friendship some depth in Empire.