After many rounds of double/triple pressing the hatch release THEN having to lift the hatch itself, even after trying the pennies trick, I found a French vendor that apparently makes 'rear trunk lift reinforced springs' for the 350/370Z:
https://www.opentop.fr/370z-1?lang=en
Shipped to the US it cost just under $70 at current exchange rates for the springs alone. They should be here in about a weeks time, but since I've read virtually nothing about them I figured I'd play guinea pig and see if this remedies the rear hatch lift woes paired with Z1 struts.
Stay tuned for pictures and full review!