[FR] Bar chart corners roundness

[Buta1234]

Please describe the idea

Hi, would be great to have a parameter that controls rounding radius of bar chart.
Currently, it's calculated automatically. It's looks fine for thin bars, but when it comes to wide, staked charts, the bars take on an oval shape.
I couldn't find this feature in the documentation.

Thank you for the genuinely impressive integration!

[mauritsivs]

also, when stacking bars, each bar is rounded so you get multiple 'ovals' on top of eachother, would be nice if only the resulting total stack would be rounded.