If what you're aiming for is the ability to reduce the size of the video stream in order to fit some DVD project of your own devising, then I can see why that would be more attractive than waiting until hell freezes over while the encoder re-runs.
But consider;
DVD2One makes no changes to the audio, so there is nothing to stop you from authoring a complete DVD with overlarge files (ones that won't fit onto a DVD5) and
then passing them through DVD2One.
The net result would be exactly the same and more importantly the program wouldn't need any new features and settings that would only serve to increase its complexity - something that none of us want, do we?
-Pete