There's a very, very big difference between controlling employees working on company laptops during company working hours earning a company salary, and controlling private citizens. Do whatever you like on your private devices on your own time.

Enterprise browsers are not like MDM that take over the entire machine. A contractor on BYOD can install a consumer browser and an enterprise browser side-by-side on his machine, using the enterprise browser (with its controls) for the contracting project and the consumer browser (free and open) for personal ends.