SMT capacitors come in endless thicknesses.
Connectors may have several pin length options.
Terminals come in a range of colors.
Stacking connectors come in custom heights.
Sometimes you can’t find a good .step model for an IC, and could just use a black box of the proper size.
It might even be possible to define one model for a connector family and specify the number of contacts via parameter.
This morning I thought it would be nice to enable parametric driven 3D models to improve accuracy, simplify customization, or just enable more generic parts.
One way to accomplish this would be to support OpenSCAD style models with configurable parameters in addition to the existing .step model format. OpenSCAD is an open source 3D model language that supports parametric models. FreeCAD supports direct import of OpenSCAD models and conversion to .step models.
It seems to me support for generating .step models from OpenSCAD would be a bolt-on option to KiCAD that would not require major internal rework. If the input dialog boxes could parse the OpenSCAD function header and offer places to input the acceptable parameters it would look like it parametric models were fully integrated.
I am not aware of any other PCB application that offers this type of functionality. I think it could be revolutionary.