  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.
