Not only did a lot of work go in, but after much trial and error the breakthrough ended up coming from some random mathematician that happened to be following the thread and decided to take a crack at it.

Mathematician's posting starts here: https://forums.tigsource.com/index.php?topic=40832.msg121280...

Next dev blog post from Lukas Pope mentioning this here: https://forums.tigsource.com/index.php?topic=40832.msg121719...