I have an issue that script command stopped when ddrescue outputs a lot of error and warning and filled out ram disk (only 128MB?). So I recommend to change logging directory to tmpfs (has more bigger free space) or adding an option that disables logging.
The current version of g4l has about 15M of free space after the boot process with the 128M ram disk. For most things, that should be more than enough. There are currently no tmpfs in the boot process, and would not allow the system to work on systems with limited ram. One option that I have actually thought of with ddrescue option and the possible need for space beyond that. Some users required special firmware, so the image does have /lib/firmware that has large footprint of 60+M, but after the boot, it would probable be save to just remove all of it for all or most users. cd /lib/firmware ; rm * -R -f
Don't know if any larger than that would be necessary.