Ah I see, you take a snapshot of the installation. Thank you for clarifying the process. Instead of taking a snapshot, have you tried adding a preinstall script, and add the installer -pkg command? But, quite honestly in my opinion, it would make more sense to create an installer script than to create a package. This way you don't have to keep updating the package and it will always download and install the latest. Obviously, you can't script every single app out there but at least you can minimize updating packages.