Yes. Whenever there's an update to one of the gcc packages that you have blacklisted on the changelog, just download the new version from Alien Bob's ftp. (Usually, he is up-to-date within minutes or hours, but I think it is a good practice to give him at least 36 hours to match whatever Pat does in the updates.) The you can do an 'upgradepkg --install-new --reinstall *.t?z' just like before.
I wrote a little script to upgrade all of my multilib packages beyond the core compiler components. Of course, it requires Alien Bob's compat32 tools, which are of course conveniently on his ftp right next to the gcc packages. It also requires curlftpfs for mounting your favorite mirror as a file system.
# Update the tree with the most current packages from FTP server and install
rm -rf /root/compat32/*
/usr/local/bin/curlftpfs ftp://carroll.cac.psu.edu/pub/linux/distributions/slackware/slackware-current /root/compat32/mnt
/usr/sbin/massconvert32.sh -i /root/compat32/mnt/slackware
/sbin/upgradepkg --reinstall --install-new *-compat32/*.t?z
This script, of course, is not selective at all . . . it just upgrades everything, whether it has been changed or not. Perhaps a 'slackpkg' hack is in order for this sort of thing . . . then it could easily go right along with the changelog.
I suppose, to make this script better, there are many things which could be done, including making the path to use for the 'compat32' packages adjustable with a variable at the top, as well as the name of the mirror to be used . . . but whatever, you get the idea.