According to the buildscript there is already a cleanup of documentation from within the iso:
# We do not need any documentation on the system. This frees some space. # Copyright/licenses files are ignored for deletion
And since "man" isnt installed:
root@vyos:/home/vyos# man bash: man: command not found
Couldnt then the content of /usr/share/man also be deleted to free up some space (approx 13 megabytes out of which most are compressed gz-files)?
root@vyos:/home/vyos# du -sm /usr/share/man/ 13 /usr/share/man/