Estimated completeness of the DL based cluster catalogue (without Planck SZcat selection) in the (M_500c, z) plane. The black dashed line corresponds to detection thresholds of p_max > 0.8 and S > 20. The white dash-dotted line represents the average mass evolution of a 2 × 10¹⁵ M_⊙ cluster over redshift (from Fakhouri et al. 2010). Left panel: Within the ACT DR5 footprint (13 211 deg²). The black dashed contour shows the 90% completeness of the catalogue, while the solid yellow line marks the same level for the ACT DR5 S/N > 3 catalogue at matched purity. The ComPACT achieves higher completeness than ACT DR5_S/N > 3 at fixed purity, especially for massive clusters at high redshift, while both catalogues perform comparably at low z. Right panel: Outside the ACT DR5 footprint (∼3000 deg²). Catalogue retains high completeness for massive clusters across the redshift range, demonstrating its potential to identify new systems beyond existing survey coverage.