Many CAD programs can benefit from object manipulation mode - i.e. instead of using the ball to control the camera, control the translation/rotation of an object in free transform mode. The trackball could be more controllable & expressive than the onscreen gizmos.
I have an initial implementation working for Blender, but Blender API limitations prevent applying it’s native ‘g’ and ‘r’ constraints (e.g. shift/ctrl modifiers or axis constraints like gx/gy/gz). Will need an upstream API change for that.