You won't need rocker stoppers unless you start going over the factory limit regularly.
The BeeR limiter cuts ignition, not fuel like regular limiters. It still dumps fuel in,so your'e more than likely blow the cat out,possibly damage the turbo,make a lot of unwanted noise(possibly illegal as well) and generate a bit more heat.
The only good thing is you will be able to come back onto boost quickly especially if your running a bigger laggy turbo