Marginalised 1σ errors on cosmological parameters, relative to their corresponding fiducial values for the baseline model of dynamical dark energy. The error bars for w_a represent the absolute error, σ, for this parameter since a relative error cannot be computed for a fiducial value of 0. Each histogram refers to a different cosmological analysis or observational probe. We show in blue a GCph analysis that neglects magnification, in orange a GCph analysis that includes magnification and assumes a 10% prior on the measurement of the local count slope (realistic scenario), and in green a GCph analysis that models magnification assuming a perfect knowledge of the local count slope (optimistic scenario). For comparison, we show in pink the constraints from the WL analysis and in violet the one obtained from the probe combination GCph + WL + GGL.