im not sure, but seems to me that Jedi Master Yoda may have confused Superbit.
my sincere apologies if i am wrong.
“Roll your own” Superbit?
In other words rip a BluRay disc to your pc and re-encode it to dvd.
however Jedi Master Yoda’s explanation does seem quite relevant.
Thing is some movie’s would still not fill a dual layer disc due to there run time and the fact that a dvd’s combined max bitrate of the audio and video is 9.8mb.
So if your dvd had a run time of say 80 minutes, audio was 5.1 448kbps then the max bitrate for your video would be 9352 it think that even if you set your avg bitrate to say 8800 you may not fill a dual layer still.
and my help to explain your concern
fail to live up to its billing due to the use of a poor transfer, and in some cases, only six out of 8.5 gigs being used on a dual layer disc.
if one could take a standard dvd and upconvert the video to higher bitrate before burning, i would not do it. i only use single layer media and am very happy with the results.