you are talking of 6 segments in a 280um pad… are you sure you need a better resolution?
ATM the only way to improve the discretization is modifying the code and changing the quasideflection value in the discretization function.
An other approach would be to allow arcs in polylines pads in kicad format … I remember there was a discussion about it…
the tool internally is using a parameter to auto adapt the discretization of the curves… you can increase the quality changing this parameter, but this will increase the number of segments, increasing a lot the file size in many user cases.
As I said a better option would be to ask kicad devs to add arcs to polylines format in i.e. (fill) zones and pads.
I wouldn’t think so… 6mils is a typical minimum trace in a standard pcb which mean about 150um … then your curve would be quite near the pcb fabrication resolution
Maybe here: https://gitlab.com/kicad/code/kicad/-/issues/4493. But TBH I’m not sure how this would work. KiCad already supports different kinds of arcs as primitives. The problem is that it internally seems to convert them to segments or polygons. Just look closely how rounded rectangle pads work.