Large aperture coronagraphic spectropolarimeters offer unique possibilities to study the off-limb corona using polarized diagnostics, including those that probe the ill-measured coronal magnetic field properties. Here, we investigate the formation of the prime coronal lines targeted by US National Science Foundation’s Daniel K Inouye Solar Telescope. We synthesize observables through advanced, high-resolution, and finely-structured, 3D MURaM coronal simulations. To do so, we have built and optimized Python-based synthesis modules that calculate the polarized line emission for multi-level atoms including the role of electron and proton collisions. We provide detailed benchmarks of these modules, in specific against tools provided by the Chianti team (in the scalar limit), both to validate the code and provide a primer for the line-dependent aspects of the polarization formation. The synthetic maps allow us to describe and predict polarized features within the array of multi-wavelength observables available. In addition, we comment on the opportunities provided for, as well as the challenges faced by, the analysis of the apparent polarized fine structures.