Marginalised 1D and 2D posterior constraints for parameters fσ₈ and ϵ from fits to the Flagship void-galaxy CCF measurements in four redshift bins. Contours show the 68.3% (1σ) and 95.5% (2σ) confidence intervals obtained in the case of perfect reconstruction (blue), realistic reconstruction (light red), and realistic reconstruction with added redshift error (dark red). Dashed crosshairs indicate the true values for the Flagship cosmology.