In the "-I" approach the biggest consideration comes from module movement. If the modules move from /some/location to /another/location only one place (/usr/bin/perlcron) needs to change and all the programs using those modules are repaired. When using findbin/lib each program itself has to be repaired. At one site i was at we moved boxes 4 times in about 7 years, each move with changes to the names of the file system paths. In that case it wasnt for cron, but to ensure a working production environment. As soon as i fixed the initiator-script all the processes worked under the new locations. I also use this method still on my home boxes, various windoz and linuxen, each with its own customized initiator script to let it run in that environment.

I would only add that if the scripts and the modules are going to maintain their relative positions in the file system before and after a move, then no change is required with

use lib "$FindBin::Bin/../path/to/modules";
[download]

However if there's a risk that the modules might move in relation to the scripts, then huck's solution is certainly more flexible.

Thanks,
cbeckley