ChatterBox uses encrypted pings (smallish data packets) to communicate connectivity, presence, and other vital information. Pings are necessary for your cluster to be aware of how to best deliver messages and also to remain aware of new devices, moving devices, etc.
If you disable “mesh syncing” in your mesh settings, you will disable sending of pings. If you want your device to not be sending RF, that might be good for a short time, but that may significantly impact the performance of your cluster.