I export with all the boxes unchecked, which gives you a one-group mesh but with all the groups still as parts. I then use Max's select by element to detach out the one I want to morph. After I make the morph I import the original detached part as a part, then apply the morph I made to it. I then save the prop and transfer the actual morph to the CR2 with CR2Editor. This works, I've done it dozens of times. Just be aware if the part is rotated you get weird results, as morphs are strictlt XYZ oriented to true directions, not oriented with the part you are working on.