Abstract
It is shown that there are globally defined Lagrangian distributions on the stable loci of derived$\mathrm{Quot}$ -stacks of coherent sheaves on Calabi--Yau four-folds. Dividing by these distributions produces perfectly obstructed smooth stacks with globally defined$-1$ -shifted potentials, whose derived critical loci give back the stable loci of smooth stacks of sheaves in global Darboux form.