Nicely written Wouter. I was holding off sharing my methods to see what you wrote. I teach a very similar method on the workshops, but do a few things differently. First, like you, I do not use the grayscale conversion in LR, but de-saturate. A step I add is next bumping contrast up pretty significantly. Then I adjust exposure, recovery and fill to taste (usually needed after the contrast bump), then if I feel the need for a further tweak (I don't very often) I can hit the luminance sliders to adjust tonal response. Did not ever try the camera adjustments trick though -- very clever!
Cheers,