Two-dimensional boundary-layer transport of a magnetohydrodynamic (MHD) Jeffrey tri-hybrid nanofluid over a moving porous plate is investigated under non-Darcian (Darcy–Forchheimer) resistance with convective heat and mass exchange. The present formulation adopts the relaxation-dominated Jeffrey limit ( \(\lambda _2=0\) ), thereby retaining viscoelastic memory effects while excluding retardation-time contributions. The model incorporates Joule heating, Rosseland thermal radiation, and temperature-dependent thermal conductivity; nanoparticle migration follows the Buongiorno model with Brownian diffusion ( \(N_\text{b}\) ) and thermophoresis ( \(N_\text{t}\) ). No Arrhenius reaction term is included in the final governing equations to ensure full consistency between formulation and parametric analysis. Similarity transformations reduce the governing equations to a coupled nonlinear ODE system for the stream function, temperature, and concentration fields subject to dual Robin boundary conditions. The resulting two-point boundary-value problem is solved using fourth-order collocation (bvp4c) with adaptive mesh refinement and strict defect control. Numerical consistency is verified through limiting-case recovery (Newtonian limit, vanishing MHD and porous resistance, constant conductivity, and zero nanoparticle migration) together with truncation-domain sensitivity tests. The engineering responses \(\textrm{Re}_\text{x}^{1/2}C_\text{f}\) , \(\textrm{Re}_\text{x}^{-1/2}\text{Nu}_\text{x}\) , and \(\textrm{Re}_\text{x}^{-1/2}\textrm{Sh}_\text{x}\) are analyzed systematically. Increasing magnetic parameter M thickens the momentum and scalar layers and suppresses wall transport; for representative baseline conditions, increasing M from weak to strong regimes reduces \(\textrm{Nu}_\text{x}\) and \(\textrm{Sh}_\text{x}\) by approximately 8–15%, while \(C_\text{f}\) exhibits the highest sensitivity. Stronger Darcy–Forchheimer resistance similarly attenuates interfacial gradients. Suction enhances all wall metrics, whereas adverse plate motion may induce shear reversal. Radiation elevates heat transfer with negligible influence on wall shear. Brownian diffusion slightly reduces \(\textrm{Nu}_\text{x}\) while thermophoresis enhances \(\textrm{Sh}_\text{x}\) under convective mass exchange. Beyond numerical simulation, a data-driven surrogate framework trained on the verified solution archive enables rapid multi-parameter prediction of wall metrics with high accuracy, providing an interpretable design-support tool for porous MHD transport systems. The proposed relaxation-dominated Jeffrey tri-hybrid framework establishes a consistent computational benchmark for coupled non-Darcian MHD transport with variable conductivity and convective exchange.
