I hope I got the point now:

...
\startcolumns

\the\titlefootnotes

\kern-\rawcountervalue[address]\lineheight % dirty trick

test\footnote{test}

\input knuth

\stopcolumns
...

Massi

Il 18/05/22 10:07, Ross ha scritto:
> Dear Massi,
>
> Thanks for your solution. But the thing may be related to the
> \appendtoks macro. It doesn't work to put just \setnotetext there.
> \note works fine, so that's the reason I need the "full functional macro".
>
> Maybe I didn't get the point, so if it's not too much to ask, could you
> do it on my MWE?
>
> PS: sorry I have to use another email account because my institute
> mailbox took forever to get the message before my government (China)
> finishes auditing it.
>
> Best wishes,
> Zhichu
>
> On Wed, May 18, 2022 at 3:36 PM mf via ntg-context <ntg-context@ntg.nl
> <mailto:ntg-context@ntg.nl>> wrote:
>
>     Is this what you mean?
>
>     \starttext
>     Hello\footnotetext{Footnote without mark}.
>     \stoptext
>
>     Kind regards,
>     Massi
>
>     Il 18/05/22 07:55, Zhichu Chen via ntg-context ha scritto:
>      > Hi everybody,
>      >
>      >
>      > After some attempts to put footnotes in a mixed 1&2 columns
>     layout, I
>      > decide to put marks in the one-column environment and flush them
>     when
>      > entering the two-column environment.
>      >
>      >
>      > The code is ugly but the result is acceptable. Except that the
>     invisible
>      > footnote marks do generate something in the main text, so there's a
>      > blank line for each footnote.
>      >
>      >
>      > Here's an MWE:
>      >
>      >
>      > =============================================
>      >
>      > \definenote[address]
>      > \setupnote[address][rule=off,location=text]
>      >
>      >
>      >
>      > \definenote[putjustmark]
>      > \setupnote[putjustmark][location=none]
>      > \setupnotation[putjustmark][numberconversion=set 2]
>      >
>      >
>      > \definenote[putjustnote]%[footnote] % if footnotes need to be
>     grouped,
>      > uncomment the second argument and the line after \the\titlefootnotes
>      > \setupnote[putjustnote][textcommand=\gobbleoneargument]
>      > \setupnotation[putjustnote][numberconversion=set 2]
>      >
>      >
>      > \newtoks\titlefootnotes
>      >
>      >
>      > \def\thanks#1{\putjustmark{#1}\appendtoks \putjustnote{#1} \to
>      > \titlefootnotes}
>      > \def\email#1{\putjustmark{#1}\appendtoks \putjustnote{#1} \to
>      > \titlefootnotes}
>      >
>      >
>      > \appendtoks
>      >    \setcounter[footnote][0] % this looks stupid because it has no
>     effect
>      >    %\setupnotation[footnote][numberconversion=numerals]
>      > \to \titlefootnotes
>      >
>      > \definenamespace
>      >     [addr]
>      >     [type=module,
>      >      name=address,
>      >      command=yes,
>      >      setup=list,
>      >      parent=addr,
>      >    ]
>      >
>      > \define[1]\useaddress
>      >      {\setnotetext[address][#1]{\namedaddressparameter{#1}{name}}}
>      >
>      >
>      > \starttext
>      >
>      >
>      >
>      > \defineaddress[fst][name={Name of Institute or Affiliation, City,
>     Country}]
>      > \defineaddress[snd][name={Name of Secondary Institute or
>     Affiliation,
>      > City, Country}]
>      >
>      > \processcommacommand[fst,snd]\useaddress
>      >
>      >
>      > The Title\thanks{Work supported by somebody.}
>      >
>      >
>     Me\email{myemail@some.where}\high{,}\note[address][fst]\high{,}\note[address][snd]
>
>      >
>      >
>      >
>      > \placenotes[address]
>      >
>      > \blank[medium]
>      >
>      > \startcolumns
>      >
>      >
>      > \the\titlefootnotes
>      >
>      > %\setcounter[footnote][0] % why it's necessary to set the counter
>      > outside the token if I define [putjustnote] as [footnote]?
>      >
>      >
>      > test\footnote{test}
>      >
>      > \input knuth
>      >
>      >
>      >
>      > \stopcolumns
>      >
>      > \stoptext
>      >
>      > =============================================
>      >
>      >
>     ___________________________________________________________________________________
>
>      >
>      > If your question is of interest to others as well, please add an
>     entry
>      > to the Wiki!
>      >
>      > maillist : ntg-context@ntg.nl <mailto:ntg-context@ntg.nl> /
>      > http://www.ntg.nl/mailman/listinfo/ntg-context
>     <http://www.ntg.nl/mailman/listinfo/ntg-context>
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>     <https://bitbucket.org/phg/context-mirror/commits/>
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>      >
>     ___________________________________________________________________________________
>
>      >
>     ___________________________________________________________________________________
>     If your question is of interest to others as well, please add an
>     entry to the Wiki!
>
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>     archive  : https://bitbucket.org/phg/context-mirror/commits/
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>
>
>
> --
> Best Regards
> Chen