Yes, I have read what he said about elliptical. In fact, this is my 2nd read-through.Yes, I have a copy. It's a good primer. I went a lot further with the maths than the book does. If you want your tailless aircraft to work over the full CL range, you need to variable twist or things get very, very out of whack away from your design point. For instance, lots of drag at cruise if you wash out the tips enough for a safe stall. Have you got to the bit where Nickel says that elliptical distributions are the best way forward?
VB, I have no illusions of being able to teach Al anything, but I'd be very interested in hearing how he may have overcome some of the obstacles I have come up against. specifically, getting it to work fairly well over the whole CL range without delving into the wonders of wing warping.
But keep in mind that there has been research done since this book was written. Even Prandtl himself, that developed the lifting line theory, later on stated than bell-shaped was better than elliptical. And the Hortens also used bell-shaped, at least in their later designs. This, for some reason, has been practically ignored.
And Nickel himself states several times in the book that you will never get perfect elliptical, only "good enough" (whatever you want that to mean).
As for morphing, I remember one idea where the wing tips were sliced like a loaf of bread and then covered with a flexible membrane. The slices are mounted on a tube running span-wise. Only the very tip slice is fixed to the tube, and the tube is then rotated to get different twists.