On a hunch, I found a solution. I added \\ instead of \par at the end and goit exactly what I wanted.

\enabletrackers[context.trace]
\starttext

%\framed[align=flushright,frame=on,offset=none,width=106.400bp]{\colored[r=0.000, g=0.000,
%b=0.000]{\switchtobodyfont[11.0pt]\setupinterlinespace[11.5pt] \rm [My]\\Application\\(Component)\par}}

\startMPpage[instance=doublefun]
draw textext("\framed[align=flushright,frame=on,offset=none,width=106.400bp]{\colored[r=0.000, g=0.000, b=0.000]{\switchtobodyfont[11.0pt]\setupinterlinespace[11.5pt] \rm [My]\\Application\\(Component)\par}\par}");
draw (textext("\framed[align=flushright,frame=on,offset=none,width=106.400bp]{\colored[r=0.000, g=0.000, b=0.000]{\switchtobodyfont[11.0pt]\setupinterlinespace[11.5pt] \rm [My]\\Application\\(Component)\\}}") shifted (200,0));
\stopMPpage


\stoptext


G

> On 25 Apr 2020, at 00:51, Gerben Wierda <gerben.wierda@rna.nl> wrote:
> 
>> On 24 Apr 2020, at 18:40, Thomas A. Schmitz <thomas.schmitz@uni-bonn.de <mailto:thomas.schmitz@uni-bonn.de>> wrote:
>> 
>> 
>> 
>>> On 24. Apr 2020, at 18:19, Gerben Wierda <gerben.wierda@rna.nl <mailto:gerben.wierda@rna.nl>> wrote:
>>> 
>>> \starttext
>>> 
>>> \framed[align=flushright,frame=on,offset=none,width=106.400bp]{\colored[r=0.000, g=0.000,
>>> b=0.000]{\switchtobodyfont[11.0pt] \setupinterlinespace[20pt] \rm [My]\\Application\\(Component)}}
>>> 
>>> \stoptext
>>> 
>>> and if I change the value to 0.6, only the first line break gets packed somewhat. But I can’t get the entire paragraph inside the frame packed. I played around with the placing of setupinterlinespace in that snippet above, but nothing really works so far.
>>> 
>> 
>> At the end of your frame, you need an explicit \par to make the change of linespacing work:
>> 
>> \framed[align=flushright,frame=on,offset=none,width=106.400bp]{\colored[r=0.000, g=0.000,
>> b=0.000]{\switchtobodyfont[11.0pt] \setupinterlinespace[14pt] \rm [My]\\Application\\(Component)\par }}
> 
> Thank you, that works. (Can’t put in the images to show, as this gets my message over 100k)
> 
> But it turns out, I have an additional problem because I am doing this inside a textext() from METAPOST and that seems to strip the \pars again. Tracking ConTeXt:
> 
> cld             > tex > f : 8 : picture pic; x:=33.000; y:=53.000; w:=133.000; h:=53.000;pic := ApplicationComponentLogo( w, h, (0.686,1.000,1.000), 0.200, 1.000, (0.000,0.000,0.000), 1.000, 0.700, (0.000,0.000,0.000), 1.000, "\framed[align=flushright,frame=on,offset=none,width=106.400bp]{\colored[r=0.000, g=0.000, b=0.000]{\switchtobodyfont[11.0pt]\setupinterlinespace[11.5pt] \rm [My]\\Application\\(Component)\par}}\par") shifted (x, -y); draw pic;path AllNodeIds_idIC;  AllNodeIds_idIC := pathpart pic; pair AllNodeCenters_idIC; AllNodeCenters_idIC := center pic;
> 
> which looks OK (this is lmtx passing the string to ConTeXt using the lua context() call). The \pars are still there.
> 
> Then later, when METAPOST is at it and that same string is used to put into textext(), it results in:
> 
> cld             > tex > w : - : \MPLIBsetNtextX{3}{\framed [align=flushright,frame=on,offset=none,width=106.400bp]{\colored [r=0.000, g=0.000, b=0.000]{\switchtobodyfont [11.0pt]\setupinterlinespace [11.5pt] \rm [My]\\Application\\(Component)}}}
> 
> 
> Minimal example:
> 
> \enabletrackers[context.trace]
> \starttext
> 
> % Works OK:
> \framed[align=flushright,frame=on,offset=none,width=106.400bp]{\colored[r=0.000, g=0.000,
> b=0.000]{\switchtobodyfont[11.0pt]\setupinterlinespace[11.5pt] \rm [My]\\Application\\(Component)\par}}
> 
> % Doesn’t work:
> \startMPpage[instance=doublefun]
> draw textext("\framed[align=flushright,frame=on,offset=none,width=106.400bp]{\colored[r=0.000, g=0.000, b=0.000]{\switchtobodyfont[11.0pt]\setupinterlinespace[11.5pt] \rm [My]\\Application\\(Component)\par}}\par");
> \stopMPpage
> 
> 
> \stoptext
> 
> So, now I’m looking for a way to prevent textext() to eat my \pars
> 
> G
> 
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