Here's how you explained it above:
"...or whether it appears to be travelling in close proximity to a specific person who is NOT it's owner. It does this by listening out for electronic devices including other iPhones, Android phones, smartwatches, any device which communicates through Bluetooth BLE."
At that point, according to Apple's support page, what happens is that if you have an iPhone, iPad or similar device with Bluetooth turned on, you'll receive notifications that you're being tracked. In order to receive notifications you apparently also need to turn on Location Services and Find My iPhone, which seems odd to me.
It also says if you don't have one of these devices and the AirTag is on the move without its owner for a period of time, it will emit a sound. However, I've seen that the audible alert can be permanently disabled. This earlier article posted at the time of the privacy updates reveals that AirTags with silenced speakers were being sold online: https://www.theregister.com/2022/02/11/apple_airtags_stalking/
You even say, or am I misreading this, that you did this yourself: "True: and I’ve ‘defanged’ all my AirTags in similar ways (which interestingly makes them legally controversial where I live)."
150 police reports of stalking means 150 separate incidents were reported to police. That's a lot, and probably there were many more incidents that weren't. Unless you think that all the people who reported the incidents to the police are looking for compensation, I really don't understand that remark. You didn't address my observation about the 1 year battery life, as opposed to other tracking devices which have a direct connection to mobile services.
As for law enforcement, it all depends on what the law of the land says. It may well be risky to a stalker, but steps can be taken to reduce the risk to arguably acceptable levels. The one thing that I cannot get past is the near field aspect of this service. It allows the power consumption requirements for a working device to be minimal, allowing it to remain serviceable for many months at a time.
Bottom line is that I'm still not reassured. If there's anything that I'm still not getting I'd really like to know.