A picture tells a thousand words, an animated gif tells a thousand pictures, and a video is probably going to far.
I don't understand what your talking about here, I've tried opening a few instances of B4a, without issues when I scroll. I'm not even sure you can open a 2nd code window in the IDE. I've only got one.
I think if you where clearer in your question, you would get more/some input from those who could actualy help you.