Values measured for Δlog age, Δ[Z/H], ΔE(B-V), and ΔlogΣ_*, following Eq. E.1, from the distribution of each one of these four quantities within the star-forming ring of NGC 3351, and in its surrounding disk, using each one of the sets of templates described in Sec. E. We find that the MILES young templates, with the most metal-poor metallicity bin removed from the grid offers a good compromise between improving the young and metal-poor feature, reaching younger ages than our fiducial set of templates, and not leading to noticeable additional artifacts neither in the stellar mass surface density, nor in the stellar extinction map. See discussion in Sec. E.6.