Unfortunately there’s not much discussion of open trackers in this community, but on that other site there’s an “OpenSignups” sub you could keep an eye on. Watch for general trackers to make a post, then you can built a reputation/ratio on those trackers and continue your way up the ladder

Either that or just watch the sign up page for the site you want to see when it’s open.

Tools like https://ipleak.net/ provide torrent leak checkers. You need a browser to view the results, but they provide a magnet link you use in your torrent client to assess what information it is giving out.

In theory if everything is set up right it should show exclusively IP/location information associated with your VPN