What is the device/connection item in the sidebar, and why does it show a name?
That sidebar item shows whether the app is connected to your physical Supernote over your local Wi-Fi ("Browse & Access"), separate from the cloud. When connected, it reads the device's own name (for example "Supernote A5 X2 Manta") straight off the device. This local connection is used to fetch your actual handwritten notes (associated with a task you're syncing) — it is NOT how to-dos sync (those go via the cloud). If you don't want notes fetched or attached to a task when you push it to your task apps, you don't have to enable this feature.