Shifted BH masses, after stellar feedback expels 99% of the gas, with respect to the initial BH masses for a gaseous stellar cluster with total initial mass M = 10⁶ M_⊙ containing ~1000 BHs, for several star formation efficiency and half-mass radius, i.e., compactness, values of the cluster. Each subfigure was generated by a set of ten simulations. The left column corresponds to subsolar metallicity (~0.1 Z_⊙), the right column to low metallicity (~0.01 Z_⊙). The solar metallicity case, not shown here, requires about double or higher compactness to have the same effect as the subsolar case.