Isn’t the concept of a theoretical warp drive predicated on the principle that while matter/energy can’t go faster than C through space, an area spacetime can move faster than C relative to another area of spacetime? This is why we see very distant galaxies redshifted in a way that should be impossible if it weren’t for space itself stretching faster than light. If gravity is just a bending of spacetime, why can’t gravitational influence or gravity waves move at whatever speed spacetime will allow?