As Pat has brought this up, the idea or reason for including the Survey Code Library is so that field data in MTools that has codes that are not in the Survey Code Library, allows the user to either edit the code(s) to what they are supposed to be or add a new code with the attributes required. Then once edited, the user selects Create Magnet Drawing and the displayed data in Office won't require any editing as codes, layers and attributes all match the Survey Code Library.
Currently there is no tool to edit topo data and get the codes to match existing attributes or add new codes.