I’ve come across a snag. When using parentheses in Arabic footnotes, they are flipped. In any earlier email (http://article.gmane.org/gmane.comp.tex.context/91501/match=setupdirections+bidi+global), you had advised adding the following:

\startsetups[note:footnote]
  \setupdirections[bidi=global]
\stopsetups

\setupnote[footnote][setups=note:footnote] % align=righttoleft


However, if one does this with your patch, the second footnote gets dropped. Here is the MWE: