It takes a lot of things to happen before a post gets federated to another instances.

This thread is supposed to explain it: https://lemmy.ml/post/1408175

Cross-instance content transmission is so poor, that de-federation is a moot point.

You effectively have to sign up for your own lemmynsfw account if you actually want to access most of the content that is posted there.

Irony because here I am posting cross-instance.