The manual 'ipfilter.dat' from bluetack is a number of there filters pre-checked/merged, using there own 'Blocklist Manager'
then its presented as a download on there backup site (in emule file format (including filter level lines and such)).
Another unique Blocklist Manager feature allows us to merge all adjacent IP ranges together to help minimise overall file sizes and help improve the efficiency of IP blocking programs.
what this feature will do is get the raw PG file format and just copy the lists together into one file, like you say.
Less efficient then going through a checking/deleting/merge/cut process (another system to write :S), but as you said, Last entry wins.
