You want to use it only locally (on your home), but it can’t be a local-only instance.

By “local-only” I meant on-device

You want to e2ee everything, but fail to mention why.

Privacy and security.

There is no reason to do that on your own network.

Networks are not a trusted party in any capacity.

I do not know why you want to use a VPN and what you want to do with it. Where do you want to connect to?

A VPN such as ProtonVPN or Mullvad VPN are used to displace trust from your ISP into your VPN provider and obscure your IP address while web browsing (among other benefits that I don’t utilize).

What is the attack vector you’re worried about? Are there malicious entities on your network?

These are good questions but not ones I can answer briefly.