Yes, it's less useful if you have multiple applications to pack. It does not take too long, though, and you could always have distinct versions of PAR::Packer in separate that get loaded using the PERL5LIB environment variable, or specify them in the respective build scripts. Probably a pain to update, but at least you get the more recent PAR::Packer which has several useful options such as for packing unicode (--unicore) and module sets (e.g. -M List::).
There is also the process at http://www.zewaren.net/site/?q=node/116 which you might have some luck with.
