The purpose of archival is to link data to the currently registered location. This is important for public sensors, as public users may look to nearby sensors for information, and scientists may use sensor data for research. By permanently linking data to where it was collected, this helps to ensure data accuracy.
For private sensors, this is less of a concern as the only way to access the data is by using information contained in the registration confirmation email. So long as your sensor is privately registered there’s no need to archive it at each location you visit. Just make sure you archive the sensor before re-registering it as public.