Boost is good at any elevation. Here in Alaska we are regularly below 1500 feet. What you need to be aware of is that every 2500 feet you loose about 1 psi of atmosphere. So you can run 1 psi more boost to get the same horsepower and the engine doesn't know the difference. So for example if guys are running 8psi boost at 5k feet, at 1500 you should be running 6-7.
One other thing to take note of is that engine temp will make a engine detonate easier. So if you're running in low snow conditions you could detonate at a boost level that's safe when in snow. Error on the safe side of boost levels and run good fuel in all riding conditions.