It would be nice if we could round the edges of rectangles. Also to be able to set how much of the edge gets rounded.

Yeah, we were waiting until we did our native drawing tools for this. We could add a separate rounded-rectangle component in the meantime. It would be awkward on the existing rectangle, because you can turn edges on and off individually, which would be weird if you added rounding on top of that. That said, a rounded-rect component would be a fine addition.

This will be in 3.1.3 on the standard rectangle component. It only works of all of the edges have the same width.