View MAC addresses of local bluetooth devices I have never connected to
I've been spoiled by the Apple Developer tools, so I haven't needed to use any command line tools.

https://developer.apple.com/download/more/?=bluetooth

In the additional tools download for your Xcode version (get Xcode from the App Store even if you have a developer account). The link above probably requires a paid account, but might work for free developers.

Bluetooth explorer and PacketLogger are two tools suited for your task. The former would be the best tool for scanning Bluetooth radio and deconstructing the advertised devices that are in range.

It's got a ton of other tricks and tools like dashboards, RSSI sweepers, throughout testers, but if you need professional level first party tools, I'd recommend this.