The problem is that it's also implemented so badly. When you start dragging a Tab you get this area which pins the tab if you drag the tab over it. But the area already activates when the tab isn't even above it, and is still quite a bit to the right...
Please disable this feature by default or make it a context menu item. If it makes it to the final version in current form you're going to get a ton of feedback on this.
Came here looking for this (or to report it if it wasn't mentioned yet).Please make a configuration option to switch the tab pinning off. It's annoying me multiple times a day since the browser updated, I would never want this feature for me personal...