Same type of plots as for J0136 in Fig. 3, here illustrating the robustness of differential photometry by showing the result from only using two of the worst available RS. With only two, their light curves will be near perfect reflections of each other, but the target light curve is still remarkably well corrected. This supports the conclusion that the variability detected in the observation of J0138−0322 (2018) is significant, despite a lack of available RS.