You can move the options list when edit mode is on by holding m i believe, you can move it to the left side of the window, put the window where you like it, enable borderless and hide the menu by pressing the cross, right click returns it. If im understanding the problem you are having correct that should help?
*EDIT: i realise that would mean when you right click to return the menu it will be offscreen again, ill update so the menu appears where your mouse is when you right click while holding m instead of to a set position. Also ill change how stretching the window works so the black bars won't show at the edges.