If an experiment that was branched out but abandoned and forgotten, but still possibly useful, then I think it's better if it gets an entry in the documentation

If an experiment that was branched out but abandoned and forgotten, but still possibly useful, then I think it's better if it gets an entry in the documentation. The source repository is a workplace, not a museum. Just create a `bla-rearchitecting-experiment.md` in your `doc/` and paste the relevant code and a paragraph or two about what it does, why it could have been better and why it was abandoned. Now your history is in the place it should be, and not cluttering up the workspace of your successors.