I'm interested to know whether nested sections are supported in the new
structure code (strc-*)?

Using the following to test, I don't get a section and subsection, but
rather two sections. The log file notes a "missing \stopsection".

\starttext
\startsection{Section}
\input tufte
  \startsection{Subsection}
  \input knuth
  \stopsection
\stopsection
\stoptext

Am I missing a setup command somewhere in the new structure code that
enables nested sections?

Thanks,

Kevin