The goal of this feature is to create CD/DVD ISO with only MP3 file to be play on Hifi system or car radio with MP3 playback ability.
When I want to burn a MP3 CD for my car, since I've got titles in various format, I need to convert them to MP3 before burning. But JSymphonic is already able to transcode file and to limit the amount of title to a given space !! It will not be so hard to extend that to CD/DVD ISO instead of Walkmans !