The problem isn't so much those who are cheating, of which there are some, but fewer than most people think, the problem is with the law makers. Correct me if I'm wrong, but we used to have a perfectly good rule only 6 years or so that said "No titanium or other super alloys allowed" despite everyone with a brain cell saying allowing it would be a bad idea, (including an article from a well known engine tuner) what did they do? Over turned the rule, the costs go up, the servicing intervals go down, the engines rev higher, become more difficult to ride. etc etc.
Rev limiters. Been on the table for years, been a solution for years. I've been involved in the discussion about them for years. will not happen because the only way to enforce it is for every promotion to have 14 of them, and issue them like transponders in road racing before a meeting and get them back after wards. But that involves investment, so don't hold your breath.
