Comparisons of single-exponential fit outputs for 3 differing user choices. The orange fit is obtained by fitting the data using Eq. (1), as in the top right panel of Fig. C.1. The green fit is obtained by linearising the data before fitting it with the linearised form of Eq. (1). The blue curve was obtained by fitting the data with a variant of Eq. (1) that includes the addition of a constant offset as a fit parameter. The corresponding estimated decay times are indicated in the legend, highlighting the significant variation arising from these user choices. The data was recorded by STA at 325 kHz around 17:50 UT on 18-Nov-2020.