I just noticed that even thought in the install section of the mod says

Modified Core Files
A few core Zen Cart files must be modified to work with the Dynamic Filter module.
If any of the core files this distribution uses have already been modified (because of another third party module being installed for example) then the changes for the respective files should be applied manually by copying across the appropriate sections of code required for the Dynamic Filter module. These sections are clearly marked (with “// bof dynamic filter x of x” and “// eof dynamic filter x of x” comments) within the sample files provided in this distribution and should be easy enough to copy across, especially if a “diff” software package (such as DiffMerge or WinMerge) is used.
The modified files can be found within the 'core file overrides' folder in the distribution as follows.
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In the supplied mod file /includes/functions/functions_general.php there are other line with code changes. That are not commented with “// bof dynamic filter x of x” and “// eof dynamic filter x of x” comments. So I would not know what to merge.