Quote Originally Posted by Laraul View Post
Starcraft II let's you select which audio device to use. And the game does let you choose which display adapter to use.
I'll admit that I think this is a shortcoming, but the game really has no way of detecting when a device has been hotplugged (most software requires a restart if a device has been plugged in, this includes mice/tablets in photoshop) It would still need to be a manual setting change.

That said, what you may consider doing is leaving the headset plugged in but muted when not in use, or the main speakers muted if you only use the headset.