Interesting idea!
One thing though: as I recall, in its climactic montage in which the unique aspect ratio was used, Abel Gance’s Napoleon alternated between one single 4.00:1 image and a 4.00:1 triptych, in which each third would have a different image, essentially creating a split-screen effect albeit three ways instead of the typical two. Abel Gance achieved the illusion of the ultra widescreen was, after all, by displaying three 1:33 (full screen) images side-by-side. Because the illusion wasn’t always seamless, a good bulk of that movie’s final montage relies on the triptych effect with different images instead of one single one.
That said, I think it’d be worthwhile to try the triptych effect, instead of always relying on a single image cropped to 4.00:1. Lightsaber fights could be especially fun to play with in this regard.
Examples of the 4.00:1 in action can be seen in the Napoleon restoration trailer: