In the preamble I have the following setup for the chapter header setup. There is one chapter I want to have a different heading setup with some less spacing, what would be the easiest way to achieve this?

\setuphead

  [section]

  [style=bold,

   before={\vskip 4mm},

   after={\vskip 1.5mm}]

What I do for a chapter that has different requirements is to define a new heading based on my normal chapter. Be sure to include it in the contents list as well if you show a table of contents, and similarly include it in the pdf bookmarks.

There may be other, perhaps better ways to do it, but this works well.

%% RVchapter can start on recto or verso, chapter on recto only

\definehead [RVchapter][chapter]
\setuphead  [RVchapter][
                        page=yes,
                        before=
                       ]
\setuphead  [chapter]  [
                        style=\tfc\HeadFont,
                        page={yes,right},
                        ...,
                       ]
\setuphead  [section]  [
                        style=\tfb\HeadFont,
                        ...,
                       ]
\setupcombinedlist     [content]
                       [list={chapter,RVchapter}]
\placebookmarks        [chapter,RVchapter,section,subsection,subsubsection]
                       [chapter]
                       [force=yes,number=no]

--
Rik