2D transmission spectra maps. For each target, an example of transmission spectra is shown in tomography in the planetary rest frame in the region of the He I triplet, as a function of wavelength and planetary orbital phase. The contact points t1, t2, t3, and t4 are marked with horizontal blue lines. The regions affected by OH contamination are masked. For some planets, some residuals are left at the position of the Si ~ 1083 nm line (highlighted in pink). This is due to the depth of the line (see e.g. Krishnamurthy et al. 2023; Zhang et al. 2023). Dotted black and red lines mark the position of the He I lines in the stellar and planet rest frame, respectively. Lines with black squares mark the position of the strong H₂O telluric line at around 1083.51 nm. The corresponding 2D maps for all the investigated nights are shown in Fig. A.2.