Previous commenter is correct. Encryption in Bittorrent is not about privacy but to combat traffic shaping (throttling). I'm not too deep into the protocol and can't say whether the 'torrent of interest' (infohash) is sent in plaintext prior to establishing encryption.
However, you operate as a public node on the DHT (basically the network) and in order for other users to find you, you publicly search+advertise your own loaded torrents (this is the default).
Very advanced Deep Packet Inspection may be able to intercept even that information if we are speaking of ISPs, but their sole interest is usually to limit your bandwidth (is this connection a Bittorrent connection? Yes/No). Anyone interested in tracking you (for whatever bullish reasons) operates as a regular Bittorrent user and needs no packet interception, they just connect to you.
If you use a 'private tracker', then you are 'public' only within this tracker (DHT is disabled and you only receive peer lists from the tracker itself) - other users connected to this tracker know about you.
Back to your question: You are better off using a separate client where you add this 'other' category of torrents. This is much easier to manage and to use. Also don't forget about VPN (that supports port-forwarding) and full disk encryption with a tool like Veracrypt.
