Left column: Pearson coefficient ρ calculated for each pair of expected and reconstructed 21 cm plus thermal noise maps. The value in parentheses is the average correlation calculated over all frequency channels. Right column: reconstruction error of the 21 cm signal power spectrum η calculated as an average over the multipole range 30 ≤ ℓ ≤ 270, on each frequency channel. The value in parentheses is the average error calculated over all frequency channels. Top row: comparison between the results of ρ and ν for the MD30 and GD30 configurations (different synchrotron models). Center row: comparison between the results of ρ and ν for the MD30 and MD30+CBASS configurations (inclusion of an independent foreground observation). Bottom row: comparison between the results of ρ and ν for the MD20, MD30, MD40, MD60, and MD80 configurations (different numbers of frequency bins).