One thing that is probably not a bug, but a bit tedious: the new half-window is always offset from the from the one under it. I have to keep dragging them back to the same position at the side of the screen.
I do that to avoid accidentally clicking on the window behind it when trying to click on the scroll bar, and to avoid obscuring part of the window on the other side of the screen.
I get the logic of offsetting them a bit, but I think it's of limited utility, especially now that I can switch rapidly between windows using a side button on my Logitech mouse. MacOS Monterey/Firefox 147.0.1
