<p>Additive manufacturing of thin structures by powder bed fusion (PBF) presents challenges related to melt pool instability and thermal stress accumulation, which often lead to morphological defects and print failures. In this work, we investigate the influence of different scan strategies—continuous scanning in fixed and alternating directions, and spot melting—on the morphology and stability of single-track-thick walls using high-fidelity, three-dimensional mesoscopic simulations of the electron beam PBF (PBF-EB) process. The simulations describe melt pool dynamics and heat transfer with a micron resolution using a thermal lattice Boltzmann method coupled with additional physical models and methods required for the multilayer PBF-EB simulation. Our results show that during spot melting, the hydrodynamic instabilities are suppressed, which enables the formation of defect-free ultrathin walls. This effect is explained by the observed differences in melt pool dynamics between continuous and spot melting strategies. These findings demonstrate the potential of spot melting for high-resolution metal additive manufacturing and provide insights into simulation and experimental techniques for spot melting in PBF.</p>