A-D hypersurface of $su(n)$ $\mathcal{N}=2$ supersymmetric gauge theory with $N_f=2n-2$ flavors

In the previous letter, arXiv:2210.16738[hep-th], we found a set of flavor mass relations as constraints that the $\beta$-deformed $A_{n-1}$ quiver matrix model restores the maximal symmetry in the massive scaling limit and reported the existence of Argyres-Douglas critical hypersurface. In this letter, we derive the concrete conditions on moduli parameters which maximally degenerates the Seiberg-Witten curve while maintaining the flavor mass relations. These conditions define the A-D hypersurface.