Is there a way to radius only certain corners?
No, not the way you are thinking. This would require a proper “Fillet” tool allowing fillet/round/radius functions to be applied to an object which we don’t have yet. It is on our list of things to do. You can add your support for this additional feature and vote it up here: https://lightburn.fider.io/posts/64/the-addition-of-a-fillet-round-radius-tool-to-round-2-entities
Currently, you can use the ‘Node Edit’ tool and change the corner to smooth or set a radius for all corners of a rectangle using the ‘Corner Radius’ in the ‘Shape Properties’ window, then remove undesired radius using the ‘Node Edit’ tool to change the radius back to a corner node.
Awesome, Thankyou for the info!