The style of chapter is significant bigger as the style from section, but it looks like the style from section and subsection are about the same. I have a workaround with the following:
    \setuphead[section][before={\blank[3*big] \testpage[15]}]
    \setuphead[subsection][before={\blank[big,small] \testpage[10]},style={\bf}]

This works reasonable. But it would be better if I could find out the definitions from \section and \subsection. Then I could make a more fine-tuned solution. Is it possible to get those definitions?

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Cecil Westerhof