Within the ESA-funded activity, LUNAR In-Situ LANding Structures (LUNAR ISLANDS), the feasibility of in-situ manufactured structures is explored. These aim to decrease the exposure of surrounding infrastructure and personnel to high-velocity particles of lunar regolith, which result from the interaction of the exhaust plume of the lander and the surface, which is covered by loose regolith. For the numerical investigation of Plume Surface Interaction (PSI), a hybrid modelling strategy is employed, combining a Navier-Stokes (NS)-based Computational Fluid Dynamics (CFD) solver for the continuum regions of the nozzle and plume with a Direct Simulation Monte Carlo (DSMC) solver for the rarefied regions. This contribution describes the automated identification of the breakdown interface and necessary division of the mesh based on that interface to allow for the use of a single mesh.