Sampleson has released a free DynoMod harmonic enhancer intended for Rhodes piano plug-ins.
In the '70s Chuck Monte took stock Rhodes, Wurlitzer, Hohner, and Yamaha pianos and customized them extensively, giving them an enhanced sound both in the studio and on stage. The "Dyno Rhodes" became popular with many recording artists in the 1970s (Joe Zawinul, George Duke, Santana, Rick James, and Larry Dunn among others).
Sampleson has designed a recreation of the Dyno mod hardware add-on into an Effect Plugin to be used for free on any Rhodes VST/AU instrument, but it's specially designed for Sampleson's Markus 88 Electric Piano.
You can download it here.