I just like ROTJ how it is. ¯_(ツ)_/¯
I suppose splitting ROTJ into two movies would have been an ideal pursuit. Draw out Vader’s redemption by having him go semi-turncoat, slowly demonstrating the error of his ways and undoing his damage from within. Maybe he spends more time with Luke, as Luke planting the seeds of doubt and pulls some of the “light” out of him.
Something akin to how Dragon Ball handled Vegeta’s redemption arc would be ideal.