[NTG-context] bodymatter and alternative=doublesided, XML documentation

Hi, I have the following problem: Using \setuppagenumbering[location={footer,right}] \startbodymatter \chapter{Hi} \stopbodymatter I always get 3 pages, but I want to have two: The recto with "Hi" and its verso, I don't want to have an extra recto! Is there a nice way to setup frontmatter to use roman numerals and bodymatter "arabic" numerals starting from 1? I know I can use \setupsectionblock[][before=\bgroup\setup...] but is there something nicer? A part of that document should be in XML, is there any documentation for the ContML available by now? Or about the XML namespacing etc. support, which is not mentioned in "XML in ConTeXT"? Tobias