Author here, I don't think it would apply well to that scenario. elfshaker is good for manyclangs where we ship 2,000 revisions in one file (pack), so the cost of individual revision is amortized. If one build of llvm+clang costs you some ~400 MiB; a single elfshaker pack containing 2,000 builds has an amortized cost of around 40kiB/build. But this amazing win is only happening because you are shipping 2,000 builds at once. If you wanted to ship a single delta, you can't compress against all the other builds.