The license states that source must be provided "on a medium customarily used for software interchange". Honestly I would think that in this day and age, a link

The license states that source must be provided "on a medium customarily used for software interchange". Honestly I would think that in this day and age, a link to a git repo or whatnot would qualify. I wonder if such issues would arise if there was simply a set of links to the source for the unmodified versions. Of course, setting up a github fork for your company's branch of a project is relatively straightforward, and also solves such issues.