\setuppapersize[A6][A6]

\definetextbackground
  [blockquotebackground]
  [location=paragraph,
   background=color,
   backgroundcolor=gray,
   frame=off]

\dontcomplain

\showframe

\chardef\kindofpagetextareas\plusone

\starttext

    \startblockquotebackground
        \dorecurse{3}{x\footnote{x}\input tufte \par}
    \stopblockquotebackground

\stoptext
