Will my device work without the firmware update or device sync?
Your SPOT Gen 3 is shipped with the factory default settings. After the activation of a SPOT Gen 3, the SPOT website may offer you the option to configure your device. Depending on how you will use your device and the settings you have selected, you may be required to perform a firmware update or sync. If you elect not to perform the firmware update or sync, you will be able to use all features of the device with the default settings, however, it is highly recommended that you perform the firmware update at your earliest convenience.
Link: How do I update my firmware?