On 12.04 at least, the target is governed by cupsd's AppArmor profile (see bug #147551) and trying to circumvent it using symlinks fails irrespective of whether the target is on another filesystem or not ("failed to set file mode for PDF file" in /var/log/cups/cups-pdf_log).
On 12.04 at least, the target is governed by cupsd's AppArmor profile (see bug #147551) and trying to circumvent it using symlinks fails irrespective of whether the target is on another filesystem or not ("failed to set file mode for PDF file" in /var/log/ cups/cups- pdf_log) .