John,
When it comes right down to it, the true optimal ignition timing changes with the weather, among a host of other factors. Modern fuel injected cars have a jillion sensors which the computer reads to determine fuel timing and quantity, let alone ignition timing for each individual cylinder on each compression stroke.
By theory, everything you state makes sense. However, there is a sort of law of diminishing returns when it comes to advancing the timing, and 40 degrees, on a street car, pretty much gets right next to breaking that law in a dramatic way.
We're here at 5,000 feet, and we don't go as far on a TR-4 as 14 initial, more like twelve
You really want to avoid detonation in one of these engines. It's not pretty.
Motorbill
From Lola to Land Rover, If it's British and has wheels, it's likely I've bloodied me knuckles thereupon