I mean, that kind of board has existed for a while. They’re usually called AI-accelerator boards, IIRC

You can download configuration files (wireguard preferably) from your protonvpn account in a web browser.

Open the network manager (idk what steam mode uses, this should work in desktop mode) and add a wireguard connection.

Add the private key, add the peer and its public key, add the dns. Save.

When you need it, simply connect to it like a regular network, in addition to your wifi of course.

This has served me well on Fedora Atomic workstation with KDE for years :)