Set the number part of course extent to the width of `0/0/10`

                \kern\tabcolsep

                \box_use:N

                  \l_tmpb_box

              }

              } &

          }

      }

      {

        \tl_gput_right:Nn

          \g_@@_table_typesetting_buffer_tl

          { \nolbreaks { #1 } & \raggedright #2 }

          { \nolbreaks { #1 } & \raggedright #2 & }

      }

    \hbox_set:Nn

      \l_tmpa_box

      { \nolbreaks { 0 / 0 / 10 } }

    \dim_set:Nn

      \l_tmpa_dim

      { \box_wd:N \l_tmpa_box }

    \tl_gput_right:Nn

      \g_@@_table_typesetting_buffer_tl

      {

        & #3 & #4~#5

        #3 &

        \makebox

          [ \l_tmpa_dim ]

          [ r ]

          { #4 }~{}

        #5

        \tl_if_empty:nF

          { #7 }

          { \marginnote{#7} }

        & #6

          { \marginnote{#7} } &

        #6

        \\

      }

  }