I want to have the formula numbers of cases environment flushed on the right like for regular formulas (not the default numberdistance=2.5\emwidth). How can I do that?

\startplaceformula

    \startformula

        \startcases

            \NC x = 1 \NR[+]

            \NC y = 1 \NR[+]

        \stopcases

    \stopformula

\stopplaceformula

\stoptext