As for the pillarbox issue, maybe a dark starry background could work? Dragonball Z Kai episodes air on Toonami windoboxed this way.
There must a be a good high res image of a Star Wars starfield out there.
Oh, God no! Not that!
People, think of it this way:
What does the letter-boxing on the DeEd segments look like? Solid Black Bars. Why does the 4:3 pillar-boxing need to be presented differently to fit 16:9. It’s practically the same thing, just on the other sides.