Detection completeness map for TOI-4602 in the mass versus semi-major axis plane, combining RV and PMa constraints. The colour scale represents the detection fraction of simulated planetary companions. The white dashed line indicates the astrometric detection limit, corresponding to a PMa signal of 3σ based on the Hipparcos-Gaia eDR3 baseline. Regions above this line are accessible via astrometry, while the inner regions are probed by RVs. The red circle marks the positions of TOI-4602 b. For context, Jupiter and Saturn are shown as icons.