Top panels: Reduced χ_d.o.f.² of the cross-power best fits. Bottom panels: Corresponding amplitude values compared to the CL23 result in red, both as function of the cleaning level N_fg. Different columns correspond to different methods: PCA, PCAw and mPCA from left to right. The filled blue circles correspond to the ‘standard’ reference analysis so far discussed; the empty orange triangle to the analysis performed with the transfer function correction; the filled green squares correspond to the analysis performed with the transfer function correction and imposing Gaussian uncertainties for the final, corrected measurements.