Do'h,
I should read your post all the way through.
The problem with the factory solenoid is that it is modulated to bleed off excatly 2psi more, it's not just an open/shut affair.
And if you unplug it, or by pass it you'll end up with 5psi not 7psi like what your after.
The only save way to get a constant 7psi is to get a bleed valve or even better, a EBC.
I've heard of people pricking holes in the wastegate hose with a hot needle, but I wouldn't be doing this !!!!
J