Holy crap, you just described what my car was doing to a "T"!
I seem to notice the most dramatic hesitation pulses, under very light throttle pressure or after I accelerate a little bit then back off the throttle and maintain constant pressure
I had my BOV so tight it was stalling my turbo when I let off the gas, so I loosened it up a bit, soft spring and full open under 5" of vacuum. From what I understand an diverter valve is either fully open or fully closed. If U disconnect the valve to keep it shut, and what you described is gone, you may need to replace the diverter valve with a "tuneable" BOV. When I installed my FMIC I was looking into a ProCharger diverter valve but the people at ProCharger did not recomend it for my application.
I would def recomend checking your turbo inlet hose, they are notorious for tearing, then bypassing that diverter and see what happens.
Keep me posted.