Product use the same spring, the spring is a little bit more compressed in the product, which is why the spring rating is 1psi higher.
The supercharger spring is specificially for supercharged cars only, if you have a quick spooling turbo it can actually push the valve open briefly before the charge gets to the manifold, dumping boost.
BOV's need a 1/4" innder diameter direct source to the manifold, smaller liners can cause delays in response time.