JeffyPoo, I don't quite get the finer points of the Plan Maturity Scale. Is it a scale of doability from the technical side, a scale of usefulness/sensibility, a scale of budgetability, or a combination?
Focussing purely on the technical side, FLW's Mile High Building is way past the 90-points-mark already.
Assuming statute mile (not nautical mile*), 1 mile = 1,609.3 metres.
Burj Khalifa (Dubai): 830 m
Currently under construction: Jeddah Tower, previously known as Kingdom Tower and Mile-High Tower. Jeddah Tower will be about 1,007 metres when finished. They changed the name because as Kingdom Tower it was initially planned to be 1.6 kilometres (1 mi) high, but the geology of the area proved unsuitable for a tower of that height.
Thing is, building tall is building expensive. While the structure itself scales pretty much linear, the cost doesn't. If vou venture into the Supertall/Megatall range, we are talking the sort of cash that would buy a nuclear carrier, including the planes (if they were availiable)
Anyway, back to the topic at hand: I notice that everyone from the original Star Wars gang is involved. So this is a also hedge to keep the funding coming, but at least it's for something useful and worthwhile this time.
* Basically the only acceptable non-metric unit. Because it's hard to be happy when you're not using the metric system.