BTW, that sentence is simply wholesale false.
The materials you mentioned are composed of atoms whose sub-atomic particles are mediated at the velocity of light. This means that an object so composed cannot be accelerated faster than light lest it be torn apart.
Traveling in some sort of “bubble” or hyper-light cavity, is outside the laws of physics as we understand them, and appear to be universally applicable across the cosmos.
And besides, why would a civilization capable of such technology even need to come here in any sort of ship anyway, as they’ve obviously at that point mastered inter-dimensionality?
As they are, as we now know, not from this solar system, why would they spend tens or even hundreds of years ranging across the galaxy, and equal amounts of time getting back to a civilization that would probably not even remember them?
Big problems.