Please add possibility to continue building an iso image from existing chroot (include commands ubuntu-defaults-binary , ubuntu-defaults-binary-clean, ubuntu-defaults-chroot )

Building customized Ubuntu .iso image using ubuntu-defaults-image takes a long time (about 2 hours) and can't be resumed from already finished chroot folder (should restarted every time from beginning).
Ubuntu Italian team developers created additional command-line tools to solve this problem, see lp:~ubuntu-defaults-it-team/ubuntu-defaults-it/additional-tools and https://wiki.ubuntu.com/ItalianCD/Tools

Please add possibility to continue building an iso image from existing chroot - include commands ubuntu-defaults-binary , ubuntu-defaults-binary-clean, ubuntu-defaults-chroot from lp:~ubuntu-defaults-it-team/ubuntu-defaults-it/additional-tools repository into official ubuntu-defaults-builder package.

Here are these commands descriptions, copied from https://wiki.ubuntu.com/ItalianCD/Tools :

 ubuntu-defaults-binary
Builds the image starting from a chroot created with a previous ubuntu-defaults-image step. It needs a cleaning step before, that can be performed manually with the ubuntu-defaults-binary-clean command or automatically by ubuntu-defaults-binary itself.

 ubuntu-defaults-binary-clean
Cleans the directory where ubuntu-defaults-image created the ISO image allowing to work manually inside the chroot for troubleshooting and creating a new image with ubuntu-defaults-binary step.

 ubuntu-defaults-chroot
Sets up a proper chroot enviroment, start it and clean it after the operations.