Aha. That explains things.
As profiles have an internal GUID in their .vap(the "Id" field), I assumed it referred to that.
I was wondering how the GUID would be predictable, as it's changed on export(and import?), but being user set that wouldn't be an issue of course.
I did see
Added, 'InternalID' author flag to profiles. This is a nullable Guid (GUid?) value that can be supplied by authors to identify individual profiles.
but didn't put two and two together(I don't personally use profile flags, if that's an excuse).
Scrolling up in the documentation it's mentioned that it's an author flag in the "GetProfileInternalID()" entry, but because these events are in their own section and preceded by the queue methods I didn't see it when searching the pdf for the event names directly.
Now that I've set that value in the .vap, the inline function works as intended(even without the main loop running).