I noticed something strange while pressure testing.
N75 was leaking into the TIP.
But only if I exceeded 1 bar, everything below that,
and it can hold pressure all day.
But when I exceed 1 bar it would begin to leak,
and leak all the way down until the system was empty.

Tried with 3 different N75 valves and all exert the same "failure" 

I think it is bleeding more air than the duty cycle is telling me?
And would cause unpredictable boost control.

Is this a feature of the valve or am I just unlucky
and have 3 faulty valves that failed the exact same way?

N75 should be able to hold just fine. You sure you have it oriented right?

yea. wgs don't need 1 bar to crack. As long as the n75 is holding enough pressure to open the WG when needed it shouldn't matter. Under boost the N75 should be dumping pressure away from the WG anyway.

IMO any waste gate system that needs 1 bar over ambient to crack the wgs is probably going to be uncontrollable.

Dual port wgs are generally used if you need a very strong wastegate holding pressure

Dunno. No experience in the matter.

[edit]: BTW I corrected an earlier post: dual port wastegates if you need more holding pressure *without* using a stronger spring.

Nope, just turned the red silicone hose up and plugged in the pressure tester(PVC pipe end with tire valve)