Even if so, it doesn’t matter how you do it, moving faster than c does bad things to causality. You’d be one Lorentz boost away from a grandfather’s paradox. I think that would hold for a region of space with lower c too, weirdly enough, because it itself could also be boosted in a way discordant with everything else.

You could just abandon relativity entirely, I guess, but that’s kind of a key ingredient in how the universe works. Making a theory like that, I’d imagine, is like baking chocolate chip cookies without the chips.