@mgiammarco the custom security example is now ready. It shows how to use existing tables for security in a Radzen application. To adapt it to your case you will have to edit the CustomSecurity.cs file so the methods use your own tables. They should be available if Radzen has inferred them from the database data source.
@SteelPhantom I see what you mean. This is a good way of handling custom security for sure. We will have it in mind should we decide to implement out of the box support for such cases.