In your explenation - i cant see a better way to do this… other than within code triggered events on overlaps or event dispatchers to play the audio (at location?)
Where are you having troubles or issues with the current engine method for Ambient Sound actors? Have you looked at the Ambient Sound Actor Guide in the docs? I’ve not had any sound problems using multiple sounds playing at runtime - both spawned at location as well ambient sound actors placed within the level for on-overlap events such as doorways, water noises etc…
Hope this helps!