I use this feature a bunch across dozens of different Windows and Mac devices from various device vendors with multiple Android phones and seemingly never had an issue.
But I'm also a person who generally never experiences the issues some people have with Bluetooth in general. If I ever have an issue with Bluetooth on a computer, I swap out the wireless chipset with an actually good one. Its almost always just bad hardware. I've only had to do that a few times in the last decade though, more modern WiFi/BT chipsets are generally pretty OK. Its the old ones that are near worthless.
Although I will say most of the time I just plug in my USB authenticator. I normally only fall back to the QR code if I don't have my keys on me.
And as an edit, I wasn't aware fully that the QR code is to help assist the BT handshake, I had assumed it was posting a signed request back to the service. My bad, my above comment isn't completely correct. Thanks for cluing me in to the BT requirement for the QR code path.
From what I understand the Bluetooth is required to ensure proximity. It isn’t actually used to transmit anything of vital importance. The QR is doing most of that. It’s just there to prevent scanning the QR through a video call and logging in from elsewhere.
Which I’m sure is great in theory. But IMO just adds even more complexity to a system that already has several moving parts and is more fragile than it should be.