(I’m picking up from a comment here that didn’t generate any answers.)
Is it possible, using one of the available footnote-packages, to provide an intelligent two-column footnote-command that switches between single-column and two-column footnote whenever two short subsequent footnotes appear? If that was possible, this would be rather amazing, keeping in mind the difficulties of multi-column-typesetting in general.
dblfnote I managed to switch between single-column and double-column between pages using
\DFNalwaysdouble, but that is rather random.
Background: Footnotes are used for various purposes. In front of me I have an article published in a linguistics journal in the 1970s where footnotes contain references to secondary literature, references to ancient authors, further qualifications of the actual argument, discussion of counterarguments, and comments that open up new questions that don’t relate to the main theme of the article. This results in the footnotes being very different in length, the references being rather short and the rest usually rather long. The typesetter handled the matter in switching between single-column and two-column whenever possible.