I have been investigating use of live-config with Refracta. I'm no expert on this stuff, may have got quite a few things wrong but here are some observations.
Live-config scripts do not run by default in Refracta, they don't have to (but can if required by user) because Refracta has preconfigured settings, (a usual Debian Live image does user-setup, hostname, ..... "on-the-fly")
Just to clarify what live-config actually does :
When live-config (or just "config") is added to the cmdline of a live session, all scripts in /lib/live/config are run during bootup, in number order. <man live-config>
It is possible at cmdline to select what scripts are to be enabled or disabled
Some of these scripts are irrelevant to Refracta, e.g. user-setup, because the live user is already configured. They usually include conditions to check for existing configurations and act accordingly, in most cases do nothing. So if they do or don't run, Refracta will be mostly unaffected
Others, e.g. sysvinit, locales, keyboard-configuration definitely do work for Refracta and may be useful.
Of particular interest is live-config.hooks, something I haven't looked at yet in much detail. That allows scripts placed in the live-media's "live" directory to run at bootup. For example, it should allow for a user to just put the current clamav defs in there and a script to install it, for a live-usb setup. You don't have to rebuild the squashfs. Or an essential nonfree firmware. The limitation here seems a user's imagination!
There is also the option of including custom live-config scripts in a snapshot, as documented in /usr/share/doc/live-config. I have done this myself successfully, with a script to set keyboard-layout according to locale.
We recently proved that locale/language and keyboard can be set from the boot prompt in this way, selecting only the relevant live-config scripts to run.
I decided to investigate what would happen in refracta if all scripts were run. It doesn't seem much of a problem with some minor exceptions and doesn't significantly increase boot time.
One exception was the gdm script. It will autologin the Refracta Live user. You may or may not want that. If it runs, on logout you get this at gdm screen:
"User Linux will autologin in : seconds"
(there is no such user, I'm guessing it's looking for the last one to login)
This seems to be set by /usr/lib/gdm/gdmlogin. This is a binary, maybe a config for it was deleted by snapshot.
This seems to have no adverse affect and autologin proceeds for Refracta's "user" (BTW, password for "user" is refracta's setting, not "live" as is debian-live default but for autologin you don't need to enter it)
If "noatologin" is passed at cmdline, the gdm script is not called and the usual Refracta gdm screen appears. That behavior is then no longer an issue.
As the config scripts run, a "state" file for each is made at /var/lib/live/config/
I listed what was in there:
hostname
initramfs-tools
login
openssh-server
policykit
refracta-configs
sysv-rc
tzdata
util-linux
(note refracta-configs, a custom one for my personal snapshot to set keyboard/locale, is there too but not gdm, I had done "noautologin")
Those are all that have run (but may have done nothing, e.g. hostname, because hostname is already set)
Others from /lib/live/config have left no state file because of early exit, e.g. user-setup, because our user is already set up.
I'm still looking at the state file list to see if any might have adverse affect on Refracta, my guess at the moment is no they won't.
Possible hiccup: initramfs-tools might do a dpkg-divert on update-initramfs, to stop that happening in live mode. The installer would need to reverse that (not difficult)
The disadvantage of using selected scripts only, e.g. locales, is more typing at cmdline (=more scope for error) also, syslinux is not very forgiving of editing typos, here the screen goes berserk and fills with text.
Much easier to just put in, for example, locales=de_DE.UTF-8 and nothing else !
No difficulty for a live usb, you edit the syslinux menu once only.
There is some potentially useful stuff to learn. Please post/discuss any comments, corrections, ideas, suggestions, amazing revelations .... on this subject here.