I post different topics on different social media sites. Sometimes I'll do #nostr exclusives, even of the message is appropriate everywhere.

NGL though, I do ActivityPub exclusives far more often because they have the ability to make followers-only posts.

Maybe some nostr dev will add a feature that gives a "friend of Dr Hax" key to everyone I approve and let me effectively post just to those people.

Bonus points if there are multiple (Friend, family, bitcoin buddy, decentralized networking pals, etc.).