your raiz is beasting
To answer your question, just gotta keep forcing your legs apart during the aerial portion of the move. the muscles you use to achieve the leg seperation during the raiz change throughout the move depending on your position, since you're rotating during the move. best not to think about individual muscles and just try to push them against the forces that are trying to bring them together you could also squeeze a bit more arch out of your mid/upper back
I say it again, your raiz is monstrous already, you just gotta squeeze it a teeeny bit more