If you are only seeing 72psi ebp I would say your wastegate is working just perfect. I am 85psi+ with larger tunes. And I think the sensor only reads to 86.xxx. Tunes change the boost too. Like I said. My truck has always seemed to be higher than normal for boost. Which doesn't help back pressure either.
72 on the mini maxx = 86.7 on the Dashdaq (@ sea level)