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Fairly minor things:

Testing standard practices (using new style, random seed)

• You were matching local examples, but we do have preferences for new tests
  Using helper function for validation.

As this is still in draft, didn't look too hard at the docs changes yet, but figured I'd point to some of our tooling early on.

As one can see in the image, there's a gap where extrema line and vertical line meet. We could investigate whether hard-codingcapstyle="projecting" makes sense for extrema lines of half violins.

https://matplotlib.org/devdocs/gallery/lines_bars_and_markers/capstyle.html#capstyle

LGTM. Thanks for the patience to go through all the review cycles!