In addition, Oculus Rift S is natively compatible with the popular Oculus platform, and doesn't require an additional layer of software to use Oculus apps, unlike the Odyssey+ which requires the [free] Revive software to run Oculus apps. On the other hand, Rift S uses Displayport instead of HDMI, and may not be compatible with older laptops.
Since Steam Support's current official response to this issue is to send people here, I want to let the community know that the best Mini DisplayPort adapter for the Valve Index is actually the adapter that is included with the Oculus Rift S. For me, every other 3rd party adapter I have tested (see below) has artifacts to some degree.