I consider full zero edge where there is no real transition between the edge and the primary grind, that's pretty much what that is, as there is no shoulder, just the final portion is polished. Hard to capture in my pics I think.
OK.... it sounds like we understand it to mean the same. :thumbup:
Just from the pictures it looks like a very defined transition from primary grind to edge.

I usually put a mirror (or sometimes semi-mirror) polish my convex edges while leaving the majority of the blade satin, but when I do it the transition comes out more blended and a somewhat fading transition without such a distinct line. Different techniques I guess. :thumbup:
Sometimes, I will put a convex edge on a flat grind where I transition the convex edge into the flat where the transition is pretty darn smooth without much of any noticable shoulder, but arguably having "some" shoulder transition - even if pretty smooth. In those cases, my lines tend to be a little more defined.
They both work very well though - with both removing that shoulder either completely or mostly. :thumbup:
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In regards to the undercoating (Charcoal layer) that you are leaving behind and referring to as "bluing for protection". I don't know for sure if that is really "Bluing". I have tended to wonder if that might not be a decarb layer (???????). I am not sure.

If it is decarb, those areas may actually rust faster rather than slower. I have a few areas of a few knives I have stripped that I have had to leave that layer - usually at the pommel. I have always made sure I have a good coat of Ren-Wax on those areas. So, I haven't noticed problems, but assumed because of the RenWax (?????)
I have never seen ANY indication that Busse has a process involving bluing the blades prior to coating. I have seen people ask about that layer and I have asked about it myself. But, I have not yet seen an answer that provides any confirmation about "WHAT" that layer really is.
Have you seen or heard something to confirm more about that layer?
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