I'm very impressed with Fatdog 813. So much capability in so few bytes!
The distribution Iso works well and all my changes (added mupdf, bookmarks to Seamonkey, and system settings) go to the Savefile and are loaded on reboot. Then tried Iso Remaster which did incorporate those changes when re-loaded on a usb drive. I created a new Savefile when powering off the Remaster. But on rebooting the remaster fails to use that Savefile - not found in aufs folder. I did point to the Savefile in Grub.cfg so I think it found it on booting (text goes by quickly).
Also, have you ever considered an in-place remaster like found in antiX?