I share the same question which you have.
When I originally submitted the parts, I submitted them as having
Solid Stud, Blocked Open Stud, Stud Recessed.
Russel decided to put Blocked Open Stud and Stud Recessed into a single entry.
I would be for splitting that into two entries. But I know that everything I
want is not going to be agreed upon, so I rested it. But maybe he can clarify
for you why.
There is, but I don't know what the reason is. It is possibly something
we could consider in the future. I have added this to list of known part variants
which we're gathering: