[blensor]

That is the onboard recording feature of the Meta Quest, it does have a way to change the video codec but the audio codec is fixed.

I'd also argue that most off the shelf stuff that records videos in any form uses AAC as a default simply because it's ubiquitous and thus has great cross compatibility.

[ErroneousBosh]

Well, I don't know, nothing really seems to support AAC. I've yet to find anything other than ffmpeg that can read it.