Simultaneously updating the inner radius, max radius and volume multiplier properties causes the audio track to go back to the beginning. There's realtime audio processing for the world ambience reverb, but apparently not for these properties (presumably others as well). I suppose this is simultaneously a bug report and a #1394416391226134678 post, but interactive audio dimmer/volume controls are more jarring as a result.
I'm wrapping up a prefab I still plan to post in #lookat-my-prefabs—it's almost done. Other complications have slowed the progress on this build. Waiting for microchips.