Side note: if you’re doing it for privacy reasons, I was reading that self hosting for just yourself will allow people to see what communities you subscribe to, based on what communities are visible on your server.

What is your threat model or goal? It could hide the device you use to connect to the instance, however a lot of actions you do on Lemmy, including all upvotes, are public to other instances.

Very loosely it would act as a caching or proxy service from what I understand.

My understanding is that when you subscribe to community “x” on server “y”, that your server “z” starts to download all of the content from that community so it can serve it to you locally. I don’t know how fast the activitypub protocol would fetch new posts/comments, if it’s real-time, or some kind of intermittent pull or push.

Your ip will only be visible in the logs of the self hosted instance, if that’s what you are asking.

VPNs have multiple effects. Which ones are you asking about?

The common ones that come to mind are:

• Preventing remote servers from seeing your real IP address
• Bypassing attempts to block access to popular Lemmy servers, either by network operators or the server itself

It won’t do the former because media gets loaded directly from federated servers. It might do the latter.