Circle-tool — subdivision functionality with arrow keys
As the "Effect > Stylize > Round Edges..." is a little bit flawed if working with short sections and third-party-scripts often show the same problem that short sections rounded often are not a circular section but some weird hyberbole of sorts I often use Circles and subdivisions of those as a stand-in if I need a round corner with a fixed radius. Up to now i have to manually draw a line from the center, rotate it by the angle I want and subdivide it with the knife.
If circles could behave a bit like the polygon tool and its arrow-key functionality to add more or less anchorpoints that make up the circle instead of the default 4 that would be awesome.
You can do Object > Path > Add Anchor Points. Although it does it evenly between each point so you don't have much control.