Suprathermal density ratio (n_st,STEP/n_st,EPT) observed by Solar Orbiter in the last 50 s upstream of the IP shock. The plot specifically highlights the transition where lower-energy suprathermals (STEP) overtake the energetic tail (EPT) in terms of number density. Vertical dotted lines mark specific distances from the shock in ion inertial lengths (d_i). The dominance crossover (ratio > 1) starts at ∼315 d_i (23 s), while the steepest gradient in the STEP-to-EPT suprathermal ratio occurs at about ∼135 d_i (10 s). The gray dotted line indicates the equivalent spatial separation of MMS4 and MMS1 (∼170 d_i) for comparison and to associate the observations of Figures 1 and 3.