Forecast posterior distributions of the cosmological parameter from simulations using the VSF, the void density profiles, and their combination. Ω_m and σ₈ can be constrained from void density profiles alone when running MCMC on a QUIJOTE simulation at the fiducial cosmology. Including the void size function tightens contours. Contours show 1σ and 2σ credibility regions. Dashed lines indicate the true fiducial cosmology.