Jeff Benjamin writing for 9to5Mac has a comprehensive breakdown on what the Apple Vision Pro Developer Strap can and can’t do. One of the primary benefits for developers is capturing video. As Benjamin writes:

The Developer Strap also lets developers capture a direct video feed from Apple Vision Pro via a wired USB-C connection using Reality Composer Pro. Files transfers of the captured feed occur via the direct USB-C connection. Users without the strap can still capture these feeds but via Wi-Fi only.

Benjamin also explains how to use the strap to access Recovery Mode:

You can also restore visionOS using Recovery Mode via the wired connection made possible by the Developer Strap. This includes downgrading from visionOS beta releases.

My experience is in line with Benjamin’s. The Developer Strap may make capturing short videos and screenshots easier, but it can’t do much else.

I will add, however, that I was contacted by a MacStories reader who tipped me off to one other thing the Developer Strap can do, which is act as a video source for QuickTime. This works a lot like capturing screenshots and video from an Apple TV via QuickTime, and the advantage is that you can capture more than the 60-second cap imposed by Reality Composer Pro. That’s great, except that the capture is foveated, meaning that the video recorded will be blurry everywhere except where you’re looking.