Thanks for the reply, Robert.
We plan to develop several editors for some domain specific languages that we either have already created, or will be creating within the next year. We want the autocomplete hints to be based on both predefined keywords as well as other objects in various parts of the configuration. We are currently exploring options for implementing the hints, including the show-hint and the XML-hint addons, with a custom schemaInfo. We will probably also have to create a new mode for our DSLs, or multiplex existing ones, and I'm not excited about writing a mode in Javascript. It looks like it would be a lot friendlier to write it in Dart, so that's why the Comid (pure Dart) version seemed attractive to us.