The issue with this is discussions will be repeated with no easy way to track the beginning of the “thread.” It is already a challenge to search for topics without having intentional duplicates. Currently, if a topic doesn’t receive a reply for a large amount of time the topic auto-closes, and if a conversation really gets off track moderators can step in. Original posters can also message @moderators and request moderation action (like closing or unlisting a topic if their privileges don’t allow them to do so on their own) or flag content which will automatically prompt review by moderators. If you can help us out by flagging the posts you think take a topic off the rails you can bring our attention to areas that need some splitting or management and we can take more timely and efficient action. That is totally acceptable and in accordance with the community guidelines.
I think at this point the feature requests category is limited to features for iNaturalist so bringing it up in the forum feedback category is the best thing to do. You can also create a poll in the topic in lieu of a feature request vote system if you wanted to elicit feedback in that form.