Best QPE candidate in QPE-less observations. We show the 0.2-1 keV light curve from the XMM8 observation. The most prominent flare, that is the best QPE candidate from all high-luminosity observations with no unambiguous QPEs, is highlighted. We used here a time bin of 600 s. The flare spectrum used to derived the quantities in Fig. C.1 (count rate and peak temperature) was extracted from a ∼1 ks time-interval around the peak. The empty circles define the period during which we accumulated the quiescent spectrum.