The BOV works, how well it’s working in your application is another question.
Regardless of the fact that even on a super soft setting or fully tightened down you were still getting compressor cavitation ( that chuffing noise your hearing ). The BOV is not the FULL cause, however the 25mm size of the BOV may play a part. Hook up the WG vacuume to the proper location then see if this still occours, it was noticed you had more power in the car probably because you’d pretty much set your WG to a ‘scramble’ mode where it was never opening… this is allot of air in that new IC setup you have. the BOV size and the lack of WG actuation are probably the culprate… hooked up right you should be back to OEM boost where the BOV will function properly.