NIP-10 (https://github.com/nostr-protocol/nips/blob/master/10.md) tell us how to manage replies. If a post is a reply the client can clearly identify the event and so the author; in my view only this one should receive a notification in the "strict feed".
The open feed could include all notification related to the root or, if the client is smart, only from the post I replied to, so the sub branch.
A tagging mechanism require users attention, and users are lazy (I daily struggle with users that cannot use email carbon copy properly...), I dubt it will work. Perhaps a personal mute thread/branch function can be useful, but would be a pure client implementation.
#[3] #[4] #[5] #[6] #[7] #[8] #[9] #[10]
ideas?
