One more thing about getting an error 6522 wrapper from SQLCLR procedures. the workaround I spoke about last week (dummy catch block) works to propagate SQL Server errors to the client without wrapping them in the 6522. But it doesn't seem to work if you want to throw your own user error (error > 50000). I've been throwing them by using a SqlCommand with the CommandText property set to "RAISERROR ….". You get 6522 wrapper here too.
This week I found out that you can lose the 6522 wrapper for your custom errors if you user SqlPipe.Execute on the SqlCommand with the RAISERROR SqlCommand rather than using SqlCommand.ExecuteNonQuery as I did. Thanks for Pablo Castro for this information. No word yet on whether either of these methods are the "official correct way" to accomplish throwing errors going forward.