As you likely know, the winding key is actually a miniature torque wrench with a planetary-geared slip that prevents you from over-winding the watch. Really quite ingenious.
A bold and audacious concept (as with the Double / Triple Split, the Zeitwerk...), including the ratchet-key wind. An amazing feat of German engineering - stacking two 6-foot long mainsprings and funnelling all that energy through a remontoire. But mostly...
As you likely know, the winding key is actually a miniature torque wrench with a planetary-geared slip that prevents you from over-winding the watch. Really quite ingenious.
And as others said, that R&D eventually led to the zeitwerk. I think it will be fascinating if one day Lange revisits the complication in an wearable format.