dmt

Yes and no - DMT (https://github.com/lmatteis/dmt) is implemented into this so you can use a single hash in the DHT for the 'site', but that will be updated to point to a new torrent infohash on every update.

libtorrent has support for it [0], as far as I know. The "research paper" you probably mean [1] is the torrent equivalent of and RFC. AFAIK at least python uses something very similar. There is an apparently Node.js implementation [2] of something that can publish a given torrent to a mutable address, and also retrieve a mutable torrent from a given address. I do not know how well this is implemented in the usual clients, but if you want it in your docker, you might want to talk to libtorrent directly, and implementing BEP 46 yourself should not be hard with the things the library has to offer. A benefit could be that depending on how you handle it, you might be able to store the tarballs docker images seem to be in their unpacked form, and just keep some metadata about what the header(s) of the tarball were, along with some file offsets.