Is there any directive for modifying the image packing behavior?
For instance, could use zst as squashfs compression instead of xz or lzma?
Or pass additional arguments to mksquashfs like exclude, files/folders -e tmp/* var/log/* -comp zst -wildcards …
Or even mount multiple readonly layers before start squashing:
mount -t aufs -o …/myfiles -o …/distrobuilder/build-dir/result …