would a reasonable simplification be average propagation speed per transistor? Originally (in true denard scaling land) 2D feature size implied speed and densi

would a reasonable simplification be average propagation speed per transistor? Originally (in true denard scaling land) 2D feature size implied speed and density (which in turn implied power efficiency)... but now that features are distorting into different shapes, those two things are not necessarily directly correlated any more, so perhaps they should be measured separately. Propagation is the tricky bit because that's where ultimately designs and usable density come into play, but these are only supposed to be rough guides - a few metrics at extremes could be enough, propagation at highest (unrealistic) density, and a density that is possible to continually drive without heat dissipation and power issues.