RER was patented and is still owned by BRP, they just licensed it to Poo and Cat in exchange for dropping other infringement claims. Think doo still has a claim against cat going for pyramidal structure. It's just business.
These guys mark each other every year, they buy each other's sleds, test and tear them apart. If you saw the R&D lot for any of them, you'd see the most current competitive models in all of them. Cat and Poo used to just swap two race sleds in the fall half way between TRF and Roseau, just to make it easy.
They all sort through the other's tech they find useful and can make work, not always legally, and roll the dice. Yeah, they ALL copy. They hire each other's people. So what. It's just business. Enjoy the ride with these awesome sleds while you can.