Grid-based approach for the LOP field selection, step 2 (fine grid). A finer grid is defined within the sky regions compliant with the P1 requirement (see Fig. 4), from a HEALPix level-4 scheme in Galactic coordinates. The 128 grid points, corresponding to the centers of 128 P1-compliant PF choices, are color-coded according to the value of the prioritization metric introduced in Sect. 3, Eq. (4). The LOPN1 and LOPS1 fields newly identified in Sect. 5 have their footprints plotted as background gray regions and their centers marked with empty magenta points. In the case of LOPN1 (left panel), the final choice does not correspond to the formally highest value of the metric (cyan diamond point; see text for details). The TESS CVZ at |β| ≳ 78° (yellow circle), the Kepler footprint (lilac region), the centers of the previous provisional fields LOPN0 and LOPS0 (black empty diamond points), and the celestial poles (red crosses) are also shown.