No, I've made some tests. c_move and c_rotate use a box shape, c_trace (with USE_BOX) uses really an ellipsoid shape.
That is not possible.. Could you please upload a small example, which will show, that c_move and c_rotate are using box shapes?
For a collision of a moving actor with an obstacle, the engine uses an Ellipsoid vs. Polygon collision detection. An ellipsoid is a distorted sphere that can emulate many collision shapes, such as cylinders, spheres or flat disks.
Greets
