Will measure the resistance tonight.
As for the grounding my understanding is the blue wire is positive and is positive when the key is on and the smec drives the duty cycle with the green wire as ground.
I have verified the green wire integrity from the solenoid to the smec. The blue wire tee's to many other items that are working just fine too.
You may be onto something with the resistance. Perhaps the resistance is too high and the smec can't actuate the solenoid fast enough to generate a duty cycle that can affect the wastegate.
The same could hold true for the stock solenoid on the car and I will measure its resistance as well to see.
Do we know what the stock resistance is of these solenoids?