It would be useful if you expand a bit on what 'scripted' means in this context. If you mean a fully customizable texture distortion effect, a la shaders, that would probably require some major changes to the rendering pipeline, and is therefore a lot of work. But if you want to change a relatively limited set of parameters (like speed and fade colours are parameters you can tweak now), that could be easier to implement. In that case it would help if you described the kind of parameter you'd like to change, though.