Looking at Lang's site, yes it is a super niche area, but there is a lot of self promotion - books, events, etc. I was first introduced to the general area of curved crease, etc was with David Huffman in the early 90s. He started that work in the early 70s. So, Lang proclaims to the the first, but salesmanship is important.

Eric himself reconstructs some of huffman's work - https://erikdemaine.org/papers/Huffman_Origami5/paper.pdf

It's an interesting area.