I've attempted to read the paper, however, while I understand the more general explanations, the math is far beyond my abilities. What is missing is some software that makes this usable!
A couple of years ago I designed this lighting system
https://www.dropbox.com/sc/qgc5295y0pcd ... kGDKIBv-pa and it exhibits some mild reflective caustics. I just experimented with a few ideas for the aperture/optics and the caustic effects were purely coincidental. Ever since I've been wondering whether there is a way to control these effects rather than rely on trial and error. The methodology described in the paper would do the job!
Indigo should be fully capable of simulating these caustics. The paper states that all simulations were done with Luxrender.