Left: MVT-T₉₀ plane, with the MVT (denoted as τ_β) values taken from MacLachlan et al. (2013), using their GRB sample. Right: MVT-T₉₀ plane for the same bursts using the MVT values (denoted as FWHM_min) from Maccary et al. (2025). Solid and dashed lines show equality and T₉₀ = 10× MVT. Some bursts are shown with coloured filled circles with the only purpose of highlighting the corresponding location in each plot. GRB 090831A, which belongs to the S₀ sample, is identified with a purple star. Evidently, the relative positioning of these bursts remains essentially invariant, regardless of the MVT metric employed.