Just an update on this re: the Bluetooth.

I had my AirPods paired previously for single use. I don't use them on the laptop (there is some latency), so I prefer the wired earphones. But it seems like Bluetooth was aggressively scanning for them. After removing them from the system, the scanning remained, but reduced significantly.

So looking at Console again, every so often, Bluetooth is scanning the network on behalf of the "sharingd" process.

sharingd is a sharing daemon that supports features such as AirDrop, Handoff, Instant Hotspot, Shared Computers and Remote Disc in Finder.

Still keeping Bluetooth off, however.

Mark.