@cannonmc:
From my experience, a torrent doesn't stay without seeders for long once it is made freeleech 🙂
Indeed… I regularly make torrents such as Terence Davies freeleech when I'm the last seeder left, and I have enough bandwidth to most leechers' capacity, yet the majority of data is downloaded from other users (total snatches 300, my own ratio 100; leechers uploaded twice as much as me). This is a good thing if you like to spare bandwidth or to accelerate downloads; less good if your objective is to increase your ratio.
At the very least, you must ensure that your upload bandwidth has capacity to upload the entire torrent ONCE during the freeleech time. In the worst case, all leechers will be stuck at the same level until the very end, your ratio for that torrent increases by 1 and they all swap their respective chunks until completion. If you are tight on bandwidth and/or you are the only seeder, you might want to add a comment and specify that in your calculations the speed will be sufficient for everyone to complete download.