The code below seems ok in \startsection[title=] but not when I program the parameter collection with \def\setupparameters{\getparameters[prefix]}
In that case even [title={enclosed value}] crashes with error message: Use of \doMacro doesn't match its definition.
Obviously I am missing something here. What?
\def\Macro{\dosingleargument\doMacro}
\def\doMacro[#1]#2{#1X#2}
The code below shows that it should be possible.
\startsection[title=\Macro{arg} no braces needed]\stopsection
\startsection[title={\Macro[arg1]{arg2} enclosed in braces}]\stopsection
\stoptext