Dürer's problem asks whether every 3-polytope P has a net. Is there always a spanning tree T of its edge graph, so that if we cut P along T the resulting surface can be unfolded into the plane without self-overlaps? A common technique in recent works is to fix a spanning tree and then study the deformations of the corresponding unfolding induced by an affine stretching or flattening of P. In the first part of my talk I will highlight landmark results by Ghomi, O'Rourke and Tarasov that emanated from this approach. In the second part I will present my own work on the unfoldability of nested prismatoids, which follows a similar ansatz.