Just make sure the Audirvana volume control is set to all the way down for the initial power up. Seems simple enough to me to avoid the speaker thrashing?
If it was a Windows machine maybe I would worry a little, but a Mac, come on seriously :)
I have done the same thing recently, Mac Book Pro with Audirvana 2 going from DAC straight to amp and there is no looking back. One less box, one less set of cables, two less sources of coloration and losses and anything extra.
Run your system like a race car. Less is best.