According to the page, you can run your own SSH proxy if you don't want to use theirs.
The way it is described suggests that the bastion doesn't have clear-text access. It shows that the SSH session is forwarded, versus having 2 distinct SSH sessions, so I hope that's right.
>>>>Please understand that by running teleconsole you are virtually giving the keyboard to anyone with a link.
Does mean i'm giving teleconsole.com the keyboard too?