I envision a modifier that “bends space” within a certain region. In the upper part of the attached image, X space stretches in the -X direction. Below that, XYZ space shrinks in the -X direction, yielding a “forced perspective” effect.
Writing a modifier shouldn’t be too complicated (at least, not MATH-wise. In terms of navigating the source code, I’m a fish out of water), I foresee shifting every vertex by some function of its distance from the threshold.