Toolbox isn't a real window (on Windows 10 at least), it's more like a popup: you can't resize or move it and you can't have it non-focused as it will automatically close when you click somewhere else.
This is frustrating to me: I like to keep the download progress visible on eg. a second monitor, I'd like to be able to alt+tab into Toolbox, in short I'd like it to behave like every other program.
Why was the popup-like nature of Toolbox chosen? Is there any chance of this changing in the future?