Today is September 13, 2023 and I found the exact way to perform these movements.

A YouTube user told me the way to do it. HCF, HCB x4 + B. (HCF means half a circle forward, that is, you start from behind and end pointing forward. HCB means half a circle backwards, that is, you start from the front and end pointing backwards.)

So that means HCF, HCB, HCF, HCB, HCF, HCB, HCF, HCB + B.

I tried a few times and it worked twice.

Regarding the speed with which you have to do it, it doesn't have to be super fast, just try to do the sequence fluidly and it will turn out well.

Today, September 12, 2023, I can confirm that it is real, I did it by playing it from retroarch on my PS3.