What it all comes down to is that if you let cocoa butter just slowly and naturally cool, you are going to get a mixture of types I-V (no VI as it takes months). The slower you go, the more type V you are going to get as the others can’t really form if the mixture is too hot - they just “melt”. So at 30 C, about all that is going to form is type V. Now, notice I say “about”. Those numbers are great in theory, but in practice, a little of all of them form at all temperatures - it is just one of those crystallization/equilibration theory “things” that I took 3 months in 2nd year Organic Chemistry to really study and understand.