EAGLE-based probability of intercepting an intergalactic O VII absorber (see Sect. 5 for our definition of such an absorber). Left panel: probability for an absorber with column density log N_O VII(cm⁻²) > 15 indicated as a function of the probed path length (1) for a blind search (solid turquoise line), (2) when targeting Bisous filaments (dashed purple line), and (3) when targeting high LD Bisous filaments (dotted orange line). The vertical black lines indicate the depths of the SDSS survey (left) and 4MOST 4HS survey (right). Right panel: interception probability in different filament targeting scenarios along a 130 (600) Mpc path corresponding to the SDSS (4MOST) samples discussed in the text: no targeting (solid turquoise and yellow lines), targeting Bisous filaments (dashed purple and red lines), and targeting high LD Bisous filaments (dotted orange and black lines). The vertical solid black line indicates the approximate detection level of current and near-future X-ray absorption instruments.