Survey hit map differences between FFP8 (using TOAST pointing) and LFI at 70 GHz. The diffuse error pattern during Surveys 1–3 was caused by differences in pointing interpolation. The matching HFI comparison is presented in Fig. 2. The FFP pipeline rejected 2.5 min of integration time on Survey 7, leaving a small deficit of hits on a single scanning ring that is not visible in this projection. A hit is assigned to a pixel where the detector beam centre falls midway through a sample integration period.