I’m not aware of any clients that will refuse to share data with clients that are configured to not upload. I don’t even see how they could determine that, especially in situations where there are no other peers to upload to, and given that stats are entirely self-reported and clients that send bogus numbers exist.

You would need a central tracker that cares, which is what private torrent communities rely on, but not public/DHT torrents such as those discussed here.

You're not that likely to get throttled by seeds though, and most torrents that are downloadable at all have a few seeds. Seeds have no way of verifying whether you're contributing the network, they're just there because someone (implicitly) decided to make the file available to whomever drops by and asks for it.