Yes, notice that the color of the bright edge garbage is basically the same color as the saber glow. That's why I think it was burned in with the glow itself.
Here's another cropping comparison, this time of the binary sunset wide shot.
Green is 0%, blue is 5%, red is 10% (thanks msycamore); cyan is GOUT, magenta is JSC, and yellow is Technidisc. (Sorry, I forgot the 97SE and '04 DVD/ '11 Blu-ray. There'd be too many colors to keep track of, anyways...)
It's interesting to note how open both the GOUT and JSC are for this shot. They're both around 5%.
The Technidisc, however, crops more than 10% off the sides - but as it's more like 2.25:1 than 2.35:1-2.40:1, it has more on the top. A LOT more. It seems to come very close to the edge of the frame.
Not sure how much this reflects the cropping of the transfers as a whole. We already know that some scenes in the GOUT are dramatically "zoomboxed."
Maybe I'll try one of those lightsaber shots next.