I strongly suspect all solutions will either be invalid, or be limited to the speed of light.

The universe seems to have a lot of weird quirks (the speed of light being 1) what they have in common is that they make time paradoxes impossible. This points to some deeper physics causing these disparate effects. Anything travelling faster than C can be configured as a time machine, and so create paradoxes.

It’s disappointing in its limitations, yes, but another step in bringing warp-driven travel into a more mainstream conversation and line of theoretical research in physics.

As with Albucierre’s proof, theoretical research always starts with the corner solutions and odd cases to reduce the variables.