So I did a little fiddling this morning....Set up a quick T fitting and used my brake power bleeder which gives pretty accurate low pressure readings since it has the reservoir tank to pump up by hand, rather than just pressurizing with a compressor....each hand pump on the power bleeder is less than .1 psi, giving pretty good control over pressure.
When I re-set my wastegate actuators, I did the closed plus two turns of a nut to snug them up. This made it so you can still spin the flappers if you try, but can't get any tighter with more turns of the nut due to the springs. What I found was the flappers would just start to crack at about 3.7-3.8 psi, just enough so I could spin them with equal resistance with my fingers...did a pump at a time for just a hair more psi, and followed the resistance so they would match. I did make about a 1/5 to 1/4 turn on one nut to get them to match up, but the initial setting was pretty spot-on. Looks like they really open up from 4.3-4.5 psi. Purged and re-started a few times to compare, and results came out the same. So, it was definitely helpful to T this up to do them with absolutely identical pressure since the tolerance is too close to measure with most gauges...probably being .1-.3 PSI variance if you don't test as a pair.