Frameshift drife is analogous to the Alcubierre drive, which is still very theoretical.
Basically the principle behind this technology is to drag a bubble of along with your spacecraft along a gravitic wave of sorts, thus never exceeding the speed of light within your own bubble, while outside this bubble reaching the speed of light or significantly exceeding it. In aviator terms, think of how an airfoil works, with the pressure differential above and below the wing. On the leading edge of the Alcubierre bubble, we contract space, and on the trailing edge we extend the fabric, creating a "differential" of sorts that allows the craft to accelerate.
Relativity is never violated. But what makes this theory only a theory is we can't even define nor quantify what space itself is--i.e. "nothing." Nothing is something, we just don't know what.
We do, however, understand that the Higgs boson is what connects fermions to the fabric of space, giving them mass. Mass being the degree of deformation fermions contribute to spacetime, and their "traction" to this fold, thus giving them motion in the presence of gravity, or, said deformation. Think the marble riding down the funnel. So through Higgs manipulation, theoretically it may be possible to anneal spacetime in a way in which we can exploit. How we do this? We aren't sure, yet. But, theoretically, utilizing this pathway could require far less energy than more conventional methods envisioned by other scientists that entail exotic amounts of antimatter and dark matter.
Of course, if we can utilize Higgs manipulations to create an Alcubierre drive, this also alludes to us using the same functions to generate wormholes. They're a whole different animal, however, because they require two points in space to tunnel--the doorway points of which to bridge through. Unless random is your sort of thing, of which the "Infinite probability drive" of "Hitchiker's Guide to the Galaxy" kind of uses. Those points require other theory.
And then there's String Theory which changes up the above entirely in different ways and has whole new implications and exotic uses.
I write about and leverage this stuff in my fiction, and have spent a significant amount of time learning and understanding the field of Physics.