Modeling on the Mg II doublets originating from the CSM shell (broad features) and the ISM of the host galaxy (narrow features) for SN 2020xga (top) and SN 2022xgc (bottom). The observed spectrum in the 2800 Å region is presented in gray and the best model fit is shown in red. The dashed blue line illustrates the SN continuum. For SN 2020xga we have marked the CaH [MYAMP] K lines from the MW.