I was also successful in getting my older HTC Vive Cosmos (from 2020 or so) working with my Framework 16 with the Radeon RX 7700S.
I am using the Vive link box, USB to the middle port on the left, and a USB-C to mini DisplayPort cable from the USB port on the back of the graphics module. I did try using a displayport expansion card, but I would only get a headset display for a few seconds before it switched from the built-in GPU to the external GPU.
I haven’t done extensive testing but poking around in the Viveport interface and a couple of other pieces of software seemed fine. I’ll give it more of a try later, but it looks pretty promising and functional.