It now works, at least starting with Data Modeler 126.96.36.1997 - just select the "Column Comments" on the "View Properties" sheet. See also the https://forums.oracle.com/message/9758004#9758004 thread.
but at least you can import views and then add column comments "manually" (of course a huge additional task if you have many views). And even here I encounter a problem if a view column is based on an expression - see my comment from today in the thread I did reference previously.
My question is about the import of Designer for those fields. This is still not solved, even not in rel 4.0
In fact even DM 3.3 imports comments, notes and comments in RDBMS from Designer repository. Though comments and notes are not accessible through UI they are there and you can include them in custom report.
Comments and notes are accessible through UI in DM 4.0