If you've every used d3, they allow you to set attributes on elements either as a constant, or using a function. For example in D3:

element.attr("width", 3)
element.attr("width", (d) => 10 * d)

It would be cool if we could do something similar in JSCAD. Where you could set segments either as a constant, or as a function of some "quality level":

cylinder({ segments: 6 }) // constant hex nut
cylinder({ segments: (quality) => 100 * quality }) // dynamic quality setting depending on what the renderer wants to do

This would allow cool things like fast on screen rendering at low quality, for example while adjusting parameters. But then can be rendered at higher quality for high quality rendering for 3D printing, or for screenshots.

I would also vote that the default be the dynamic setting, since it represents a "true" cylinder in some sense, just a question how accurately you want to approximate it.