@BrianJ First of all, a big thank you for the very interesting video, which taught me a lot. I have a few questions and requests.
Symmetry - it would be nice if the result was more symmetrical and the polygon edge on the mirror axis was straight.
The fact that you can align a UV mesh to curves is great. On the other hand, I used Unfold3D for many years and I would have unwound the UV mesh first, then relaxed it and used the resulting unfold as the basis for creating a texture. I think often you don’t know what the relaxed UV island will look like and when I align the mesh to a shape I estimate, I distort it more than to be expected in reality. I miss a relaxation function. Or does it already exist?
You first align the lower edges on the left and right. That’s how I would have done it in Unfold 3D. Here I wish I didn’t necessarily have to use a curve as a reference. In Unfold3D I can choose between simply fixing horizontally or vertically (in Unfold3D there is no alignment to curves). Would this also be possible for the Rhino Unwrap tool?
After fixing the lower edges, I would press the Relax button in Unfold3D, which would minimize local squeezing/stretching. My goal is not to specify my shape, but to achieve the most physically correct unfolding possible. At the moment in the screenshot above, relaxing would provide the ideal result. Could add a relaxation function implement to Unwrap in the future please?
One more example where simple horizontal/vertical alignment would be useful - in the final result I notice that the top center ISO line is not straight in the middle. Here I would select the polygon edge in Unfold3D and set it to vertical.
A relaxation function would also ensure that this local stretching at the seam would disappear by itself.
I know, unwrapping is a science in itself and not easy. It would be nice if a relaxation function was possible and I hope a horizontal/vertical alignment is easy to implement.
After I wrote all this, I had a direct look in Rhino and it looks like my wishes might already be possible, there are still tools hidden there. 
Is there a video about this?