A more appropriate, less close minded method of asking for permission to use mods within a modpack. Have you seen the list of requirements for a private modpack?!
How about a method similar to that implemented in games of old where you connected to a server and, any modifications necessary were downloaded to your client. I was working on something like this myself but, due to time constraints the project had to be abandoned. This of course, does not apply to any developers who give blanket "Don't claim my content and, we're cool" permissions, they have my thanks.
