I mean it depends on how you reach the speed of light. Straight up propulsion correct but then you cant get the energy required for that, if we can somehow figure out a way to bend space to create a “warp” bubble the internal zone should act as we expect, but the energy requirements there are still fucking enormous and im not sure that would be feasible without us inadvertently creating a singularity that we could never escape from so there are just problems inherently there for either method lol