I like to round off the corners of board outlines, to help fit into enclosures which often don't have sharp corners. My workflow so far has been to draw a rectangle on the outline layer as a guide, then draw curves in the corners, then delete the line segments that make up the guide rectangle and make new segments to connect the curves. Switching to the OpenGL renderer seems to help with selecting segments, I have no idea why this would make a difference though.
This is a little time-consuming and it's especially painful if I have to adjust the size of a board. Is there a better way to do this? Ideally I would like a rectangle tool that allows resize through dragging or typing lengths and has a corner radius option. I've thought of scripting this externally and editing the pcb file as the text defining the outline is quite simple but an in-program solution would be even better. Any ideas?