Notes. The (usable) exposure for all XMM-Newton observations (in ks) refers to the EPIC-pn camera. We also report the quiescent bolometric luminosity (in units of 10⁴³ erg s⁻¹) for all observations. For the XMM1 to XMM11 observations, L_{bol,  quiesc} was taken from Miniutti et al. (2023), and we used exactly the same procedure and spectral model to estimate it during the XMM12 observation. As for the Chandra observation, we report L_{bol,  quiesc} as estimated by Miniutti et al. (2019), but we point out that L_{bol,  disc} in the Chandra observation is highly uncertain due to the degradation of the Chandra ACIS detector that forced them to ignore data below 0.4 keV, as well as to the possible appearance of a soft X-ray excess component not easily disentangled from the disc emission above 0.4 keV. L_{bol,  disc} may be underestimated by up to a factor of ∼2.5 even in XMM-Newton observations due to systematic uncertainties on the intrinsic optical and UV disc emission (as discussed by Miniutti et al. 2023). The last column indicates whether (unambiguous) QPEs were detected during the exposure.