In addition to using arcs as design elements, I’ve often used ellipses as well. It turns out that its efficient to approximate ellipses as a set of circular arcs. The efficiency is a bit esoteric, essentially CAD tools typically approximate eclipses as a large collection of straight line segments. This can result in longer execution times when these run on CNC machines. Approximating the ellipse as circular arcs allows the CAD program to use a small number of arcs as tool paths instead. Several years back when I first began thinking about this approach, I undertook a bit of web based research to learn what has been worked out by others for approximating ellipses as arcs. There were quite a few hits for these web searches, including mathematical treatments of finding the optimal fit for a given number of arcs, including this one: https://www.geometrictools.com/Documentation/ApproximateEllipse.pdf.

One of the most interesting facts that came out was that apparently ancient Roman engineers used arcs to approximate ellipses used as architectural elements for buildings and bridges. https://www.jstor.org/stable/3620465?seq=1#page_scan_tab_contents