Inverted a K mask then desat in LAB to remove the cast in the shadows
That's a genius idea! I've never thought to try that before - that's great!
It's a nice correction Niels

and we don't insist that everything gets done in CurveMeister, so no such thing as cheating

I think that it's a little too dark (on my screen), given how saturated the sky is (although the image can probably stand a bit more saturation overall); maybe you need to reduce the opacity of the multiply move (or try multiplying through a mask?)
Thanks for having a crack at this one - and that K mask desat; brilliant!
Lee.