Simulate Game-Defined Aux Sends with Soundcaster?

Question

I've spent hours trying to figure this out and I feel like I'm losing my mind.

I want to audition and set the parameters for my environment reverbs in Wwise without the game engine running. Everything is set to "Use game-defined aux sends", which works in-engine just fine, but I'm not in-engine.

What's the workflow for this? I can't seem to find anything about this process anywhere in the documentation or in the forums.