Proof of concept: https://commits.kde.org/scratch/rjvbb/osx-integration/1260a608db98cfd3d75bf15917945b59c81b1182
The same class also adds a simulated (emulated?) Menu key that's a real saver in those situations where I'm getting more side-effects from my trackpad's 2-finger right-tap than intended effects :) R.
