[hksh]

Try out fogleman/sdf[1]. It is like OpenSCAD in many ways but the distance field model gives you offsets and fillets more easily.

[1] https://github.com/fogleman/sdf

[dTal]

SDFs don't really work for CAD. You cannot even apply an anisotropic scale without making the distance field non-euclidian, which will render the effect of subsequent operations unintuitive. Extrusion along a path is impractical if not impossible in the general case.