The center of the quilt is usually more stable than the outer edges. (from AndiR)
I like the word "usually". I made two twister quilts in which the entire center is on the bias. If it weren't heavily starched, it would be quite wobbly. I took the measurement that the blocks were suppose to be and multiplied that by the number of blocks. It worked.
I like Scissor queen's method of putting the border on top to sew it on. If you put it on the bottom, the feed dogs take in a little more and that surely can cause the border to buckle.
Measuring through the middle is quite accurate (except for the Twister), and just be sure to cut two the same, one for each side.
Sooooo! What is CDO (or DCO)???