If they would only use something like rsync or ostree at the least. But if the biggest files are archives it would require recompression. If it's more like an u

If they would only use something like rsync or ostree at the least. But if the biggest files are archives it would require recompression. If it's more like an uncompressed tar archive then it should be easier, but still it would require either a clever algorithm or the format support by the algorithm.