Right. I should add those, thanks for the feedback. It needs some other updates as well.
The struct is private because you're supposed to use the functions (the only things you are supposed to use are the ones listed in the comments in the documentation). But you're right, I need to add a mechanism to call its .destroy(). And yes, I should check if the sound is playing as well.
Overall, Sim3DSound is a neat concept, but I don't think it was ever 100% ready. The lab didn't exist back then, and it doesn't behave 100% like wc3 3D sounds, so it can definitely be improved upon.