Hi everyone, the author of the blog here. I'm glad to see the interest here on this piece!

I have slides that detail the problem setup and the mathematics, as well as a consideration of three-dimensional onions, here: https://drspoulsen.github.io/Onion_Marp/index.html

I have submitted a formal write-up of the details of the problem and the solution to a recreational mathematics journal.

I'm also happy to answer any questions about this!

I love how deeply nerd-sniped you have been by this topic. It's wonderful to be able to observe your delight in solving this. Thank you for sharing.

I feel like mathematics and many other rigorous field-friends have tons of great questions like this that are ripe for fun research. Thanks for publishing this and contributing to that world of curiosity!