Duncan Hothersall wrote:

The manual suggests that you can put index calls between a \section heading and its first paragraph without worry, but for me it breaks the page-breaking mechanism, allowing the section title to end up at the bottom of a page like this:

\starttext \section{Tufte} \dorecurse{4}{\input tufte \par} \section{Knuth} \index{Knuth} \input knuth \par \stoptext

Is there any workaround/fix?

can you try (test extensively): \def\dodoregister[#1]#2#3% {\dogotopar{\dontleavehmode\doprocesspageregister[#1]{#2}{#3}}}