I had already discovered setuptexttexts myself. But how to do it ‘nicely’ was still missing.

Thanks to Mikael and Wolfgang

Am 24.01.25 um 17:44 schrieb Wolfgang Schuster:

\setuppagenumbering [alternative=doublesided]

\setuptexttexts [margin]
[] [\framed[frame=off,width=max,height=max,align={middle,lohi}]{\prefixedpagenumber}]

[\framed[frame=off,width=max,height=max,align={middle,lohi}]{\prefixedpagenumber}] []

\starttext
\dorecurse{100}{\samplefile{lorem}}
\stoptext