I think that would be possible but I don’t think any clients implement that today? The notes are still written to the relays though so would still be visible in clients that don’t implement this type of filtering.

The other option might be to do it at the relay level. The relay would look at a user’s mute list to determine if an interaction with their notes is allowed. I’m not sure if that could be made efficient though and would rely on all relays implementing this functionality to be useful.