Just an update. I had the BPV pulled and serviced (new allen bolts and cleaned/re-greased) when the new turbo was installed. The BPV is in good shape!
Flutter went away with the new turbo and tune, so it was tune related.
The faint "tapping" noise is the
solenoid since its mounted on the firewall. Not a big deal and you really wouldn't notice it unless
radio is off and I were to point it out.
Overall happy with the valve!