I hope you don’t mind, but I’m cc-ing the xbib dev list …
Look at the fifth bullet in the two CiteProc tests you linked to in
that post. To what does the ibid in the first citation refer? In
the example where all citations are footnoted, it appears to cite
Tilley (the document most recently cited in the footnotes). In the
other example it appears to cite Thrift (the document most recently
cited in the text).
If I’m reading it right, then at least with this example, CiteProc
is determining ibid based on a single numbering space. If a
document is cited in the main body and then in the next footnote,
the footnote gets ibid. If a document is cited first in a footnote
and then next in the main body the main body gets an ibid.
This is correct; it is the current behavior.
This sounds wrong to me. The first citation a reader (who might not
be reading footnotes) might find in the main body could be an ibid.
That would be weird. It would be double weird with endnotes. E.g.,
“The senator voted for the bill (Smith, 2000). A debate ensued 
and then the senator reversed himself (ibid.)” That ibid should
refer to (Smith, 2000), not to the last citation in the endnote
discussing the debate. No? I’d think ibid should be used only if it
refers to the most recent document in its domain, whether body,
footnote, or endnote. (Word, by the way, allows both footnotes and
endnotes in the same document.)
So, for purposes of ibid, there can be one numbering space (as in
your examples), or there can be separate numbering spaces each for
the body, the footnotes, and the endnotes (as I prefer). Is the
choice something that can be hardwired, or should it be (or is it
already) a CSL parameter?
I lean toward saying Zotero should be hardwired to have three
separate numbering spaces. But if there are styles that demand
otherwise, then out goes my bias.
Have you an opinion on this?
Not exactly. You raise good points and questions. We’ve been
contemplating some changes to CSL, so we might as well add this as
another issue to settle.
Anyone have any opinions?
It’s been a long, grueling, day/month for me, but my hunch is we
start by changing the default expectations, and should only add extra
config options of this sort it it’s really needed.