[oXygen-user] pop-up of datatypes?

This may be a FAQ, in which case I apologize -- I'm in the middle of a class, using oXygen to teach RELAX NG. A student asked an excellent question -- why is there no pop-up list (nor completion) for the values of type= of <data> at attribute insertion time? (He points out it would be *very* useful.) We note that at at validation time, oXygen can tell us that "date" is OK, but "dtae" is not. I'm betting that the schema oXygen is using declares type= as an NCName, but that at validation time oXygen knows to check the datatype library specified on the datatypeLibrary= in force. Any way to get attribute value pop-up for these datatypes?