Even accepting the possibility of high elasticity & very tight actinofibril stacking, I don't think so much disappearing area is spatially or materially plausible at that size, especially the vanishing at the wristt.
As for how I would handle it, here's my own Blender rig/sim:
I'm once again expressing my scepticism for the trope of wing membranes in large pterosaurs shrinking to near-invisibility when grounded instead of being allowed to fold or buckle, even a little bit.