I can't agree more with this. I would apply this to the shading style and edges of icons and UI elements as well. I know this is probably somebody's baby, but as they teach in design school, sometimes you have to kill your baby.
These elements look quite unpolished and inferior compared to what KSP1 ended up with. Please set a goal of moving past this, smoothing out radii, and using more pixels / finer gradient shading before this goes too far and ends up being the de facto design language for the UI.