Can anyone tell me how to suppress individual numbered chapter/section/subsection/etc. from the table of contents?
The only reliable method at the moment is to create a clone of \chapter.
Also how do you set the last heading level included in the table of contents. I think I came across this, but am having trouble finding it again.
You can use \placelist where list only the headings which should appear, e.g.
\placelist[chapter,section]
or you change the list for the \completecontent.
\setupcombinedlist[content][list={chapter,section}]
Wolfgang