Exactly, the rules are only holding the electronic side of things away, like traction control, gyros and any kind of systems like that. Anything mechanical to do with suspension, diffs or geometry is legal, if it fits in the max and min measurements.
The main reasons advancements arent happening I highlighted in my previous post.
One more reason is ofcourse, most companies dont bother, because why should they, its not needed to sell cars, but maybe in the future it will be, who knows. Also many companies dont have the right people that are needed to push the envelope. There isnt enough money in the RC Racing industry. Even traxxass is coming up with all kinds of innovative stuff, because the market they are in is already alot bigger than the racing side of RC.