Followup-For: Bug #1031696 Thinking aloud: as an alternative, would adding the '-f' flag to MKISOFS achieve the desired result for both documentation and firmware files, without requiring any other changes?
(I'll mention as context that there are symlinks in the debian-faq tarball that is used as input for the on-disc documentation) [1] - https://manpages.debian.org/bullseye/genisoimage/mkisofs.1.en.html#f [2] - https://manpages.debian.org/bullseye/xorriso/xorrisofs.1.en.html#f
