The SQLStoredProcedures template (https://github.com/codesmithtools/Templates/blob/master/Templates/Frameworks/Csla/CSharp/DataAccessLayer/Internal/SQLStoredProcedures.cst) is including computed properties in the updated sql and in code: https://github.com/codesmithtools/Templates/search?q=GetUpdateStoredProcedureName&unscoped_q=GetUpdateStoredProcedureName
We'd need to update the instances above to filter out computed properties in all spots. We could do this by changing Entity.Properties to Entity.GetProperties(PropertyType.UpdateInsert). We'd accept a pr for this.