One thing I would love to see is the ability to Compile your folder structure inside UltraISO and be able to save the project to a small file (Not the ISO maybe a .uiso or something.) Kinda like with Nero you can save your compilation.
I often build very large Optimized ISO files for my Double Layer media Some of which are bootable. And when compiling them It takes a very long time. It would sure be nice to be able to build my compilation and save it before I start the burn process.
I cant imagine this would be very hard to do to UltraISO.