Dear Xara...

Create a new Rectangle with Curvature. I believe the default value is 0.2.
Enter a Curvature 0 or drag either of the Blue controls to their corner position.
The Drag can be either with the Rectangle Tool selected or the Selector Tool with object edit handles showing.

Bug - on release, a blue control drag is now only a Drag operation.
If you fiddle around with Shift-Drag & Release, you may occasionally get the blue control operating again.

Yes, I could re-enter a Curvature value of greater than 0.01 to separate the blue controls and allow them to function properly.

Bug - I have chosen to display 3dp in Xara so I can work more accurately. Others with the default 2dp entering any value under 0.1 have a display of zero curvature whereas the corners are still curved.

Bug - the hint text for Drag to resize or rotate is wrong. Rotate require Shift+Drag.

Acorn