Jeff, the rule was made to conform with Canada. In Europe they still run Mini on 950’s. I thought the cadet chassis looked way overpowered when I watched the Mini classes at Rotax Worlds this year. There were a number of bad flips in Mini.
In some Canadian series they run Micros and Minis on Vega Blues (which I’ve always found strange), which have a TON of grip. I wonder if the 1010 rule has anything to do with that. An Evo Mini on a cadet chassis shod with Vegas would be bicycling around every corner.