> Headscale seems to have nailed down the part of bypassing the firewall and doing fancy NAT-traversal

Did they really roll-their-own for those functions? I thought this was just a control layer on top of Tailscale’s stock services on the backend, are they facilitating connections with novel methods? Apologies if I’m asking obvious questions, I use ZeroTier pretty regularly, but I am not too familiar with Tailscale.