What is the option to specify the CAPTION location in \startplacefigure (I already now that you can do it from \setupcaption)?

I thought the first argument of 'location' was for the FIGURE location, and the second one for the CAPTION location, but the second one has no effect:

\startplacefigure[location={left, top}, title=A cow]

    \externalfigure[cow]

\stopplacefigure

Best regards.