I have 3 remote servers can I use tunnels to connect them to each other so I can call internal ips from each other?
It actually is possible, I have done it for my own servers. You just have to deploy a Cloudflare Tunnel to each server, create dummy interfaces with any unused IPs, make these IPs available through the private subnets option within the tunnels and then deploy the WARP client using Service Auth tokens. For it to work you obviously have to tinker with the WARP and Network settings to only route the tunnel traffic, nothing else (Include mode). But once thats set up, everything works fine and its truly location independent, without VPN!