If your points are symmetrical and you construct a plane from each set of points, your midplane should work fine. Unless the edge faces are so rough. you could also set the part up with a flat piece of stock touching each face as a datum simulator. Something mechanical rather than code.
If your points are symmetrical and you construct a plane from each set of points, your midplane should work fine. Unless the edge faces are so rough. you could also set the part up with a flat piece of stock touching each face as a datum simulator. Something mechanical rather than code.