That’s a funny name. I’da called them chazwazzers.

This is just for security purposes since otherwise any vulnerabilities in Sunshine could be exploited.

And to be clear, I don’t mean a privacy commercial VPN where you’re paying to hide in a crowd or change your location but just an encrypted tunnel between two (or more) computers (although they more or less use the same technology).

Sunshine server plus moonlight client should do what you want (preferably behind a VPN such as Tailscale or wireguard).