to be consistent, these shouldn't be exposed in the API like this...
I'm not very happy with the whole 'type ID map' paradigm (particularly its lack of static analysis guarantees), but the most important thing right now is to get this stuff out of the API so that plugin devs don't try and abuse it. We're not going to change the whole system days before PM5 release.
making this nullable was based on the invalid assumption that global sounds have no position, but it turns out they _do_ still use the position to make the sound come from the correct direction.