Already possible,
I prefer to backup to workstation then from there do your DVDRW backup. Using Darrell Mays backup2ws software you may adjust the size of the media from 650,000,000 to 4,500,000,000 and have it create multiple dvd size files that can then be copied to dvd with your dvd burning software.
Advantage of the above is that most restores can be done from the workstation without actually having to use the DVDs. If more than 1 dvd then you will have a complete backup over night without needing to be their to insert a disk. Next day insert disks and finish previous nights back up to disk.