Gigatron, thanks for your time! Yeah, I actually modified this depth effect to modify X and Y shift amount based on the distance from the center of the screen, and then used the stepping that that parallax shader I linked used to make all the pixels line up correctly, and it's all working.
Yeah, the way I was going to about it is going to sound stupid to anyone that knows anything about GLSL, I was just trying to hack the displacement to do what I'd just stated above. It doesn't make much sense not to just use this Depth Map effect and extend it though.
Regardless, I'll be uploading this new effect here soon.