Unless i misunderstood, I believe the point of this post wasn’t talking about defederating, it is asking about protecting the users data from Meta if federation happen, and for that point it is what I said, his data is as protected as before, federated or not, Meta won’t get access to any extra data from being federated than it already has access to now.
Defederating is another entire discussion that is really up to the instance admin, self hosting is the only way to really guarantee anything if you want that much deep control of your data and fediverse experience.
Isn’t that a setting, and you can make it connect without launching big picture, so it’s basically just pc streaming?