I'm looking for the same thing. What I have found is that if I use the Preload for the most recent 100 posts, and check the option for "Preload mode (garbage collection only on legacy cache files. Recommended.)" on the Preload page, the homepage of my blog gets preloaded but then doesn't update with the latest posts.
If I check the "Clear all cache files when a post or page is published." option then the homepage is updated properly, however it also deletes all of the supercache preloaded files regardless of whether or not the "Preload mode" is enabled.
Now, I'm not sure but this might have something to do with my permalinks, which were set up some time ago to include "index.php" in the URL and so I've also had to remove that from the list of rejected strings. In any case, would like to be able to exclude the homepage from Preload. Cheers!