Can you answer my question please? Even with your proposed law, there are only two options - work exactly 40 hours and risk PIP; or lie on timesheet.

Which would you choose? Based on "be complicit in your own exploitation", I am guessing you'd choose option 1, work exactly 40 hours, don't get things done on time, and make your boss unhappy? Well, good news: you can do this today, even if you are exempt, no need to ask for a law.

(I suspect you are hoping for option 3, "get my boss to approve overtime so I can work extra hours, get all the stuff done, and get extra $$$". This won't happen. If the boss is evil, they really see no upside in this so they won't approve the overtime. If the boss is nice, they won't give you too many tasks to begin with.)