Post-maximum (+85 to +337 days) spectra of ASASSN-20jq plotted in velocity domain with respect to the rest wavelengths, as indicated on top of figure panels, of [Co III] (left), [O I] (middle) and [Ca II] (right) lines. The pair of the black dashed lines in the middle panel represents the rest-positions of the [O I] doublet components. The pair of red-dashed lines represent the position of the [O I] doublet redshifted by 2200 km s⁻¹ to best match the observed feature beyond +229 d. The [Ca II] doublet in right panel shows a systematic redshift of ≈1700 km s⁻¹ throughout the evolution.