[NTG-context] vertical position of \overparent in concrete math

I have a formula involving \overparent to be typeset in kpfonts and concrete. There is no problem with kpfonts. But the \overparent in concrete is just too high. I can adjust the position with [distance=-1ex] . Is there a better way to adjust the position? Like using goodies (don't know how)? Thanks in advance! \starttext \start \setupbodyfont[kpfonts,10pt] \m{\overparent{ABCD}=100\pi} \stop \start \setupbodyfont[concrete,10pt] \m{\overparent{ABCD}=100\pi} \m{\overparent[distance=-1ex]{ABCD}=100\pi} \stop \stoptext