Users will not be able to use download accelerators without direct links.
JFYI, even with direct links hotlinking will not be possible, as direct link valid only for user (IP) who generated it (and during few hours only).
But then, why does the speed limit disappear if I allow direct link?
If the direct link applies only to the user who generated it, users will see the usual "download" button to download the file but how will I limit the speed of that?