I just found something interesting.
Trackers that allow adding them to a torrent directly, in your downloader is sufficient (so not even into the torrent file), when requesting tracker information that torrent will be added to the tracker if not existent yet.
No need for the tracker to know the torrent before-hand.
You just add:
Yes, there’s already 2 (I found).
Oh, I just found out the following one is also an open tracker of that kind.
I already saw it in different torrents, but never knew it was that kind of a tracker.