It would be great if the hardlinker could both take the options it needs on the command line and extract those options from the config file.

Right now you can't specify the directory to link, but you must specify whether you're a tier1 mirror. -t/--tier1 should come from the PREBITFLIP setting.

Add these options:
-d / --dest to take the directory to link. Get rid if -d for debugging.
-f / --filelist to override the name of the file list.

Probably want to enable some expansion in the file list for the module directory, too.