> If you change the package defined in the bottom most layer, all 49 above it are invalid and need re-pulled or re-built.

I also initially thought that that was the case, but some tools are able to work around that [0] [1] [2]. I have no idea how it works, but it works pretty well in my experience.

[0]: https://github.com/hhd-dev/rechunk/

[1]: https://coreos.github.io/rpm-ostree/container/#creating-chun...

[2]: https://coreos.github.io/rpm-ostree/build-chunked-oci/