The term "resolution" is perhaps one to be avoided in this context, as it tends to be associated with 2D pixel density.
Strictly speaking, as I understand it, when you dial up increased image quality in SldWks, you are decreasing the size of the polygon mesh.
Such a mesh underlies any 3D model, whether surface model or solid model. What look from a distance like smooth curved faces are actually internally calculated as flat facets. Because facet edges are not shown in the middle of a face, this faceting is only evident, on screen or in 2D output, where two surfaces meet, or on a silhouette edge.
It's not a question of vector output resolution, but of internal process granularity.The vector output quality is inevitably affected, because the problem is upstream (garbage going into the 2D visualiser= garbage coming out)