I have detected one bug on you Visual Designer for OA. For reproducing it I'll explain a few steps and use some imaginary tables and domain.
Well, let's assume a system that only log users in. You design the database first and create a Users table, a UserLogins table, a UserGroups table and a UserPermissions table. You setup the PK and FK.
But as a mistake you setup UserLogins as many-to-one with Users, UserPermissions many-to-many with UserGroups and then you go and Add Domain Model on your project.
This would generate the rlinq file and so on (let's assume using attribute on nested namespace on multiple files).
Then you see your mistake and go on database an setup the FK for UserGroups and Users using a join table (many-to-many). After saving you go on Visual Designer, right-click and select Update from Database. Select the tables you updated and Finish.
Visual Designer wont update (may be the way you want, but I think it should, but this is not yet the bug I mentioned, this is more a lack of feature that would be nice if implemented). Then if you delete the entities and try to add then again you would notice that associations now appears on Visual Designer (great!) but the IList collections arent there. If you look over the generated files the collections are there but not at the visual designer.
For making this work I had to remove the whole domain, deleting the rlinq file and adding again. Then i displayed the correct visual entities and associations and collections.