Stick with the 15" rule of thumb and then plumb it back in. Unless you have a really optimized setup, you're not going to gain anything by going to an atmo dump, state inspection problems aside. You're also not going to have any turbulence problems unless you have an undersized exhaust. This is where the 15" rule of thumb comes in, that's about the point where you're far enough away from the turbo to not have the turbo and wastegate affect each other. Basically, if there is a difference between atmo vs plumbed, you have problems with your downstream exhaust system and need to address that first. When someone can show me back to back dyno tests of a properly done street turbo setup with a properly plumbed in wastegate dump vs. a atmo dump on the same setup, and the difference is actually noticeable, then I'll change my tune. I have yet to be convinced though. I'm with Jarrod, if you can plumb it back in, do it.