Thanks for the suggestion. We use CodeMirror as the basis for our online editing experience, so we support syntax highlighting only for the languages that CodeMirror does. If Objective-J is similar to another "mode" (what CodeMirror calls supported languages), we are able to map the Objective-J extension to that mode.
Objective - J is similar to Objective - C. Objective - C so it is impossible to choose when editing. Why are all the same code highlighting works looking at the code for Objective-J, and when editing is not working?