It should be open now. Or at least, it was yesterday.

This should work, but this looks like an EPUB with DRM (since there's an encryption.xml file), so you might need to remove the DRM using something like Calibre.

Prowlarr properly shows if a torrent is freeleech for me. Maybe the feature was added after you tried it?

And Prowlarr is even better if you're also using Radarr/Sonarr/Lidar.