There is an annoying, jarring surge of noise when the Offline Mixdown (Bounce, Render, etc.) completes.
Once, as either a symptom or cause, it put the audio engine into a feedback loop wall of sound that would have destroyed my monitors, had they been on. I ripped my headphones off my head as fast as I could.
I was able to stop it by turning off ASIO Guard and then turning it back on, same session (didn’t need to reboot). Just made the setting change and clicked Apply.
Even when this “feedback wall” doesn’t happen (it’s only happened once), there is the tail end of what ever was playing that hits the audio engine once it engages after the mixdown.
There should be silence, null audio data, several seconds, pushed into the ASIO buffers to prevent this. And / or in combination with a forced muting of the audio path.
Basically, whatever can be done to stop the sound and clear the signal path.
Even a kludge, like auto-lowering the master volume for 3 seconds after the mixdown, would get the worst of it, in most cases. Maybe have an adjustable parameter to fading the audio back up after, etc.