Again, I could very well be reading this wrong, but the joins dont look necassary to me, it could look something like this

SELECT *

FROM nostr_events ne

WHERE (kind IN ($1, $2) AND pubkey IN ($3))

AND EXISTS (

SELECT 1

FROM nostr_tags tag0

WHERE tag0.event_id = ne.id

AND tag0.name = $4

AND tag0.value IN ($5, $6)

))

(this isnt directly taken from your query below, this is just an example)

This is also why i recommended the use of the composite index (event_id, name, value), which I would image would give a huge performance boost on that EXISTS check, but without being able to test it (and make sure it returns the correct results) I could be talking out of my ass