I see no reason to do it.
All sources would be automaticly transfered to this file,
Right-click filename >> Extenden options >> Swap every A4AF to this file (auto)
no sources would be droped,
You can disable sources dropping on preferences.
and even downloading of another file would be stoped if this file might recive a higher speed of download.
Nonsense. How would you know that this file can receive higher dowload speed than current? I don't think it's a good idea to stop one download, just because the other one
might receive higher download speed. This would cause all your files paused when this file starts downloading, which you can do manually, too.