Extreme High-Speed Laser Cladding (EHLA) is a promising surface engineering route for brake discs under Euro 7 brake-particle regulations because it enables thin metallic coatings to be deposited at high processing speeds with low substrate heat input. However, for subsequent wear-resistant top-layer deposition and grinding, the buffer layer must be longitudinally continuous and geometrically uniform. This study investigated defocus-conditioned process-response relationships during the coaxial-powder-fed  EHLA deposition of AISI 316L buffer layers on gray cast iron brake discs. A 5 x 4 x 5 x 3 full-factorial design comprising 300 conditions was adopted by varying the laser power P, scanning speed Vc, powder feed rate Qp, and defocus distance ΔF. Coating quality was evaluated over a 6 mm section using the C0-C3 longitudinal bead continuity, mean bead height H, and an image-derived longitudinal profile roughness. Increasing the defocus distance increased the low-discontinuity C0/C1 fraction from 24 % to 47 %. In addition, 24 conditions within P = 9-10 kW, Vc = 60-80 m/min, and Qp = 20-30 g/min remained C0/C1 at all tested defocus distances. A higher Vc reduced continuity and H, whereas a higher Qp increased H but tended to reduce continuity. Thus defocus alters the relationships between EHLA process parameters, bead continuity, and layer geometry, providing a robust deposition domain for the investigated material–equipment system.