On the Varjo discord one person has had success in getting the game going with Varjo's OpenXR by downgrading Varjo Base to 3.10.3.25. Don't forget to disable OpenVR in Varjo Base if you're going to try it, and use https://github.com/mbucchia/OpenXR-InstanceExtensionsWrapper/releases to get rid of the black square in the middle of the screen that you'll apparently get.
I haven't tried yet, but thought I'd share in case it works for others.
Update: tried it, and the game now runs for me. Also seems there's no need to disable OpenVR in VB.
A small problem: if I turn Upscaler Auto Quality to Off, I get no video in the HMD, while on the main screen everything seems fine - there's a picture, and it tracks the headset. The same story with both Temporal and DLSS. Once it's back On, I get the video in HMD.