Well, if that is the logic you wanted then congrats!
But I think it’s a very special one and requires a proper description:
I want to select 1 & 3 and have to press CTRL first! and then 1,3 for otherwise I get the 1 twice
If I now press SHIFT or CTRL accidentally 1, 3 is selected again and again (I hope there are no boockings involved!!!)
if this faux pas dose not happen and I now like to select 4 to 6 I get 3, 4, 5, 6
Ok, may be I have to read this book you suggested by Alan Cooper 
I agree it’s still not ideal. But if the control triggered the OnClick event once for every click instead of once for every item in the selection a work around would be unnecessary. I’ll probably be playing with it for some time to fine tune it. Thanks for all the suggestions.
That’s why I always opt for the practice proven 80% solution!
If you ever find anything else please let us know, but till then have a jolly click-shift-click (and not shift-click-oh)
P.S.
Not every program qualifies for a work-around just because it works, but there should be added a cancel option as soon as the ‘Selection pending’ message pops up 
even the cancel can be quick: just hover over it…
my_fast_select.py (3.1 KB)
(on Friday 13th one shouldn’t get out of bed)
and the user is entitled to know what the machine is doing (or setting the status bar non intrusively)
my_fast_select.py (3.6 KB)