I'm trying to typeset two-column text with two-column footnotes in a grid-based layout in ConTeXt. Setting all of this up is easy with ConTeXt, and in general, the footnotes are placed where I expect them to be. But I see unexpected behavior when a page only contains the first column (e.g., when the last page only has enough text for one column) or when the first column is shorter than its full height (e.g., if one or more lines at the end of it were moved to the next column because they are orphans / widows or have footnotes that would not fit in the first column). In these cases, the footnotes are aligned to the bottom of the first column. I can see how this might be an intended result, but ideally, I would like to see the footnotes set ragged-bottom (i.e., built up from the bottom of the textblock) regardless of the height of the columns, similar to what the LaTeX package footmisc does with the bottom
option. Is there any way to do this in ConTeXt?
A minimal example illustrating several instances of unexpected behavior is included below.
\showframe %to illustrate empty space in columns
\starttext
\startcolumns[n=2]
A single line of text with balancing.\footnote{Footnote dropped in column balancing.}
\stopcolumns
\page
\startcolumns[n=2, balance=no]
A single line of text, no balancing.\footnote{Footnote directly beneath text.}
\stopcolumns
\page
\startcolumns[n=2, balance=no]
\dorecurse{2}{\par\input zapf}\footnote{\input zapf}
\stopcolumns
\page
\setupbodyfont[10pt]
\startcolumns[n=2, balance=no]
\dorecurse{3}{\par\input knuth}\footnote{A single-line footnote.}
\stopcolumns
\stoptext
I typeset these using ConTeXt version 2020.03.10, as released with TeXLive 2020.
In the first example, a column with only one line of text will eat up the footnote at the end of that line if column balancing is left on. In the second example, turning column balancing off fixes this problem, but the footnote is glued to the bottom of the text rather than being set at the bottom of the textblock. In the third and fourth examples, long footnotes and even single-line footnotes placed after the last line in a column will result in the shortening of the first column, and consequently, the alignment of the footnote with the bottom of the first column rather than the bottom of the textblock.