Hi, I'm pretty late on the discussion, but I just started implementing srfi-170 to Gauche
to see how it works.

One thing I couldn't find in the discussion archive is the rationale of override? optional
argument in create-{directory|fifo|hard-link|symlink}.  It's not in underlying POSIX call.
Supposedly it's for convenience, but I don't think it can reliably be used (suppose two
process trying to create objects with the same name simultaneously), and
I feel better to leave it to the upper layer to handle various application-specific
requirements.