Has anyone looked into implementing a behavior that would allow the operator to change CIRCLE_RADIUS while in Circle mode (or some new mode) and have the vehicle continue with the same center point but using the new values of CIRCLE_RADIUS?
Working in SITL, it looks like changing the circle radius right now preserves neither the center nor the correct yaw orientation. The vehicle will adopt the new value, but will no longer point towards the center of the circle (and will no longer circle the original center point).