I have implemented a new download system that now should be able to handle giant entries without a problem.
Just press the download button and it'll generate the zip file in the background. Once generated, the download will start automatically as long as you keep the page open.
If the archive already exists, you won't have to wait at all! :D
Reminder: You have to be logged in to see the download button (signing up is free *wink* *wink*)