One of the beta testers asked at one point whether this plugin will work with OmniOutliner3 standard. Yes, it will. Installation is a little more complicated, but it works with the basic features well:
After launching OO3, the Exporter should be available (check under Help > Export > ConTeXt ). You probably will find things easier if you change the default template so that notes are not "italic" by default.
The features described in the manual under "ConTeXt Export: Basic Usage", "Embedding literal..." and "Customising styles" should all work.