Effects of apsidal precession on secondary-disc impacts. We show two different apsidal phases leading to $e_{\mathrm{app}}\simeq e_{\mathrm{app}}^{\max }$ and to e_app ≃ 0. The former is shown as lighter orbit and corresponds to an apsidal phase in which the difference between consecutive longer and shorter T_rec is maximal, with impacts occurring at approximately the same distance from the centre. Conversely, when e_app ≃ 0, the two consecutive T_rec are approximately equal, and impacts occur close to apocentre and pericentre respectively. Ascending (descending) node’s impacts are denoted as odd (even) impacts leading to odd (even) QPEs and are shown in red (blue).