We proposed a model to estimate surface topography and transition edge width in diamond-turned non-circular compound freeform optics featuring right angle transitions. The method serves as comparison basis between both full and split radius tools and takes into consideration basic cutting and tooling parameters relevant to a raster tool path, along with multiple variables, such as material response and defects, tool wear, and spindle vibrations. Principles are applied to a set of adjacent rectangular surfaces of different tilts. Fabrication tests validating the model show good agreement between the proposed calculations and the experimental results and offer insight on how and when both tip geometries should be used. We represent a useful asset for optical engineers who want to determine which diamond tips choose for their freeform applications. It can also be employed to assess the attainable surface quality and width of edge transitions in compound freeform designs before manufacturing them.