Something seems amiss in the code below. The idea is having in general figures with numbered labels, but now and then a figure without. First I thought to use [location=none] on the placement, but then the numbering is not interrupted: label-1 (label-2 invisible), label-3. That is disturbing to the reader who will think a figure is missing. The numbering and the label are suppressed by \setupcations[number=no] and reinstated with \setupcaptions[number=yes]. But this kills the space between the label and the caption. I enclose a minimal example that shows the effect. Could this be a bug?

\setuppapersize[A6][A6]
\starttext
\placefigure[][fig:1]{label with space}{\externalfigure[arrows.pdf]}
\setupcaptions[number=no]
\placefigure{}{\externalfigure[arrows.pdf]}
\setupcaptions[number=yes]
\placefigure[][fig:3]{label without space}{\externalfigure[arrows.pdf]}
\stoptext