Would you consider adding a property for "FileSource" to the Files option of the upload widget?  Then i could set the base 64 string (since the images are stored in the database).  This would make it so much easier to display an image preview for these files.  Right now I have to do a hack because this is not supported (see ticketID: 1348670).  Please consider adding this property for the next version - thank you!

Here is what the code would look like with the new property available: 

                    .Files(files =>
                    {
                        foreach (var file in Model.Attachments)
                        {
                            files.Add().Name(file.FileName).Extension(file.Extension).Size(file.Size).FileSource(file.Base64Src);
                        }
                    }