Chromebook Smart Lock - does it need BT?

[jpwattam]

I found this feature very unreliable with 2 different phones. So I switched off BT on the Chromebook as I had no other reason to have it on. With a recent ChromeOS update, I'm now being prompted to unlock my phone to unlock the Chromebook, although not every time, which is odd. Even more odd is that BT is still off on the Chromebook!

So my question is: does Smart Lock actually need BT anymore? Possibly it is working across wifi???

(I found this article but can't comment on it... https://m.androidcentral.com/unlock-your-chromebook-using-your-android-phone-smart-lock)