\enabletrackers[mixedcolumns.trace]

\starttext

    \startitemize[n]

      % \dorecurse{2}{test \par} % wrong break in columns
        \dorecurse{4}{test \par} % disappearing pre text

        \dorecurse{30} {

            \writestatus{!!!!!!}{itemize: \recurselevel}

            \startitem item

                \startitemize[n,packed,columns,two]
                    \item test \item test
                    \item test \item test
                \stopitemize

            \stopitem

        }

    \stopitemize

\stoptext
