Sound Effect track in addition to the Audio Track
not to be assigned to a clip, but to be added to the audio track line where the sound fx needs to be placed. This track can be locked in place so the audio track does not move it when changing a song, or adjusting songs. Nice to have a toggle to lock it or unlock it.
This is a trickier issue than it might appear. There is currently no way to anchor an audio track to a specific 'point' in the show per se. Audio tracks always need to be anchored relative to some other element, be that another audio track or a slide. We've found that the best way to ensure a sound effect remains where you want it to appear is to add it to the slide where that track should be heard. That audio track will then maintain its relative position as audio files in the main show soundtrack are swapped in / out.