Earlier quoted context omitted.
After I move the mouse over the back "button" at first nothing happens, it's surely nothing happening "as soon as the pointer" enters the area. Then after some delay, the "area" of the button is shown, but not inclunding the newly "empty" space, which you claim is clickable. But what is highlighted starts to the right. If my mouse is already close to the edge, it visually signals that it's not over the button, that i…
Hmm, it seems like what I've observed (I only tried MacOS so far) is what's supposed to happen, and what you got is bugged; hopefully they'll fix that soon. In the case when the button does light up the instant it becomes clickable, I don't get the perception of ‘I've moved the mouse too far’ — instead, it's easier to see why the highlight isn't bigger: I don't just get a “hint of the area I can target”, I see exactl…
The button area is visible as soon as one hovers with the mouse over the button.
Above: when the new code is turned on.
Below: when the new code is turned off.
The problem is: the area covered on hover should match the clickable area. If left of the button can't be clicked, the button is wrongly positioned. If it is intentionally bigger, the visual feedback should match it. The new code doesn't do that.