For any other Magicolor 5430DL-owning FreeBSD users, I can confirm that
this works - that ABI stuff rocks!

- Take the Linux RPM from the Minolta website.  
- Extract with rpm2cpio
- Move minolta.ppd to /usr/local/etc/cups/ppd
- Move rastertokm5430dl to /usr/local/libexec/cups/filter

Now you need to read FreeBSD Handbook chapter 10 (Linux Binary
Compatibility) for hints, but basically you add RPM components
to /usr/compat/linux until the Linux binary rastertokm5430dl finds what
it needs. The "ldd" program will tell you what's missing to stop it
loading.

A useful command is:
        rpm --install --ignoreos --root /usr/compat/linux fred.rpm

Might need to add --nodeps (but understand what's what first).

The RPMs I installed (other than those installed
by /usr/port/emulators/linux_base-8) were :

        cups-libs-1.1.17-0.9.i386.rpm
        mktemp-1.5-16.i386.rpm
        openssl-0.9.6b-29.i386.rpm
        MAGICOLOR5430DL-1.7.0-1.I386.RPM.

The first 3 RPMs can be found on
ftp://archive.download.redhat.com/pub/redhat/linux/8.0/en/os/i386/RedHat/RPMS/

The last RPM is from the Konica Minolta website.