Hmmmm … maybe this is a mac-only thing, but AFAIK dialing a delay into the Blackmagic card doesn’t affect the audio.
The whole purpose of that delay is to get audio & video in sync.
We use Syncheck to measure the delay.
So, if the audio & video would be out of sycn, Syncheck would report it.
Unless I totaly misunderstood the question.
Fredo