Yep, Lars learned GFOLD at JPL and took it to Spacex. GFOLD was invented by Behçet Açikmeşe https://www.aa.washington.edu/facultyfinder/behcet-acikmese
So I always take 'secret' 'proprietary' data and algorythms with a bit of salt, as almost every time I dug into them, it was all spin on previous public stuff.