Was just curious about this topic. Don’t know what software you were using to export STEP (B-Rep mathematical surfaces) to STL (triangular polygon surfaces) but usually there are options beyond the usual low, med, high settings that let you adjust surface deviation, normal deviation etc. Whatever name they go by in a CAD application they will facet the mathematical surfaces in STEP to much finer detail triangular facets needed for 3D printing. For example in Fusion 360, high settings on a simple model combining a sphere and cylinder gave me about 17000 triangles. However when I added custom settings to max the polygon count I got 422000 triangles. The faceted model was round enough that the limiting factor would be the printer, not the faceted representation.
fwiw (2 cents or so) … I think CAD (B-Rep) data support, in STEP or whatever format, would be massive overkill for Formware. STEP was developed to enable CAD data transfer between proprietary formats found in CATIA, Solidworks, Inventor, Fusion 360, Pro-E etc. With the advent of 3D printing the CAD vendors were forced to support faceted representations of 3D objects and that is a whole new game. They are best equipped to handle that. It is non-trivial and there are so many places it can go wrong (sliver surfaces, miniscule mismatches at tangent surfaces and so on). The translation library to support STEP files from all possible CAD applications would have to be brilliant and Formware would be bound to updates or bug fixes of that library should the need arise.