Can you explain how this is more secure than SSH to a bastion host via an out of band network?

Could you clarify a bit on "out of band" in this use case? In principle, if you have a way to access your bastion on a completely private--maybe physically separate / leased line--network, then that's going to be extremely secure, but maybe you had a different use case in mind?

Out of band could be as simple as ngrok, or cloudflare Argo - or as you suggest by a separate connection.

SSH is two factor - key + password and Argo,ngrok,wireguard to a VPS provide DDoS mitigation and attack surface concealment and reduction.

I think I’m missing what your product adds.

Gotcha. In your example: nothing. We're okay with that. The level of security that results from the setup you described is what we are hoping Twingate will bring to people with convenience and ease of management built-in. I'm always amazed at the very wide range of sophistication that different teams and companies approach security with, and very, very few companies are at the level of your example. That's what we're excited to help change with this new product.