Hi San,
If you do not need a retrospective population of the new fields, then indeed it does not make sense to fill the setup tables with the corresponding downtime. However, be careful if you add new fields (or make changes in general) to the communication structure.
Please refer to the following SAP Notes for more information:
- SAP Note 328181 - Changes to extraction structures in Customizing Cockpit;
- SAP Note 762951 - Organization of structure changes in the LBWE.
Best regards,
Sander