I agree, this is something I'm exploring and wrote a NIP for it I will add an "unfollow" and an "unfollow only in Olas" options and something similar for Follows.

Should it be client based or kind based though🧐

It's taking a long time for devs to see this. Nostr is still way too concentrated on kind 1 networks.

This. You should be able to tell a client which list(s) to follow and what kind(s) to follow.

I strongly disagree, this should not be solved by following or unfollowing an npub on a specific client or for specific kinds, but custom feeds. The network graph should be simply represented, what is the benefit of saying Joe is connected to Sally but only regarding the topic of soccer, not baseball? If one of them wants to filter, it should be client config, not at the level of a follow or unfollow.

I think we will need topic specific social graphs for web of trust. But I agree, that should probably be handled by filters on your core graph. Maybe we can have filtered lists by kind and/or topic.