Wow, I'm not only feeling baffled, :blink: - I'm dazzled! ...
...some nice long responses but still no explanation for why the Vector CST model shows so little energy in one area compared to another, other than the obvious. Thank you Mr CST for showing us what's really going on.
For the lower ¼λ cone to operate in a non-apparent collinear fashion it would have to radiate as efficiently as the upper ½λ. If this were so, it would then show a current bloom equally as wide but only ½ as long.
It doesn't.
I believe I've now seen, and read, enough evidence for me to side with the 'negligible' radiation camp, (as per the patent explanation) accepting the entire antenna as radiating including the lower ¼λ cone, but only enough from the lower ¼λ cone to cancel the undesirable out of phase main element current, (as shown in the CST model) lowering the TOA as it elevates the upper ½λ.
Apparently the Vector is achieving a lower TOA over a conventional end-fed 5/8λ, providing the associated far-field gain but merely equaling the SGM, not providing enough gain to be a true fully radiating collinear, which is typically closer to 2-3 S-units far-field gain, a perceived gain figure I and others have witnessed on multiple occasions from the introduction of a collinear element and which I simply won't waste time debating.
...and I'd like to see that full Vector CST.
Movin' on... 
