This is how PADS layout sets ARC teardrops.
I think that ratio is a % of PAD diameter, and the teardrop polyline can match the trace width
You can see how much closer other pads/vias/corners can be placed, with curved teardrops.
It does not need a lot of segments to approximate the arc, maybe 5 or 7 a side ?
I wonder if KiCad scripts can trawl the DRC error reports/tags, as then a 2 pass could be possible, where offending teardrops are removed or adjusted.
PADS can also generate teardrops on angled entry into oval pads.
There are no teardrops on trace T junctions, they apply to "last-segment intersecting pad-outline"