I quite like Tailscale SSH for this, but I don’t have as many machines, so not sure how it will scale. You can definitely assign roles here to allow/deny SSH between hosts in your fleet though.

And a great how-to on building one https://www.youtube.com/watch?v=oq4LmYEFlHM

Did you try manually setting the TDP? In Civ VI I set it to 7W (default graphics) and it has helped quite a bit.

I mean, this is Google we’re talking about…