Well I have eventually tracked down some documented information on the elusive sharpening angles, and the vague references to the mystery two cutting edge type Augers.
This is the latest doctrine available to my knowledge, however as always if I am incorrect please let me know!
Here we go breaking News!
Note: There is also a reference to enlarging the chip extraction port. (it must have been originally small and evolved to what we see today) possibly from users enlarging them!
Some images of different augers and in particular some with two cutting edges and one with no center tip at all.
Here is the cutting angles of the primary 60 deg and a surprise of 80 deg secondary finishing, not that its unexpected but I would doubt if ever done this day.
Also some diagrams on the cutting sequence of which I guess we all know any way, I could have edited it out but it complements the article.
So all you HCM owners its now fact!
-- Regards Robert