I am stupid and this is too dense for me to understand, but I understand the algorithm (as in how to implement not how it works), except this part, select minimax p pdesign, how do I do that?

I think that's in the paper https://arxiv.org/pdf/2505.16932

In the paper they are kind enough to include the code so that I don't have to understand the math behind it, as it goes way over my head, and I don't know how to extend it to inverse square root