Ok, after dabbling around a bit more, I can now come up with the following example

====================================

\setuppapersize[A5][A5]

\showframe

\setuptolerance[vertical,stretch]

%\setupalign[line]

%\setupinterlinespace[stretch=0.1] % vertical stretching seems to kick in for stretch !=0, no matter how small

\setupalign[height]

\setupinterlinespace[stretch=0.001] % vertical stretching seems to kick in for stretch !=0, no matter how small

\setupdelimitedtext[blockquote]

                                               [style={\switchtobodyfont[x]},

                                               spacebefore={medium,flexible},

                                               leftmargin=no]

\starttext

\dorecurse{10}{

\input knuth

\startblockquote

\input knuth

\stopblockquote

\input knuth

}

\stoptext

====================================

Two noteworthy things:

1. In LMTX you’ll need \setupinterlinespace[stretch=X] with X not 0 for vertical to kick in.
2. \setupalign[line] insists to fill the last page completely.

Denis

Von: Maier, Denis Christian (UB)
Gesendet: Montag, 26. April 2021 11:34
An: 'mailing list for ConTeXt users' <ntg-context@ntg.nl>
Betreff: AW: \setupalign[height] and \setupalign[line] in LMTX

Hi,

sorry to be such a nuisance, but i'd still love to hear if I'm missing something or if something is going off the rails in LMTX.

Best,

Denis

Von: Maier, Denis Christian (UB)
Gesendet: Donnerstag, 22. April 2021 15:07
An: 'mailing list for ConTeXt users' <ntg-context@ntg.nl>
Betreff: \setupalign[height] and \setupalign[line] in LMTX

Hi,

\setupalign[height] and \setupalign[line] seem to have no effect in a  LMTX. Do I need to change something?

Best,

Denis

```

\setuppapersize[A5][A5]

\showframe

%\setupalign[line]

\setupalign[height]

\setupdelimitedtext[blockquote]

                                                               [

                                                               before={\setupindenting[yes]\tfx\setupinterlinespace},

spacebefore=medium,

                                                               indentnext=no,

                                                               leftmargin=no,

                                                               rightmargin=no,

                                                               ]

\starttext

\dorecurse{10}{

\input knuth

\startblockquote

\input knuth

\stopblockquote

\input knuth

}

\stoptext

```