I use multiple monitors in different configurations on a Windows 10 laptop. If Firefox was last started on a monitor that is not present now, it will still open in that location and will not be accessible.
In order to get to firefox, I have to use the taskbar to show the preview and then right-click and select move. Then press an arrow key to get the cursor with the window attached to it to show up on the main display. At that point I am able to drag it around and put in a usable section of the monitors.
I would like Firefox to check if the coordinates it is opening at is within the desktop constraints and move to something close if not.