How to determine headset type in 2D app?

I'm building a general purpose 2D app using DotNet Maui. I want it to access the passthrough camera if available. Originally I was hoping that there was a platform feature I could query that would tell me if there was a camera available before pushing the permission dialog, but I couldn't find any way to do this.

My fallback is to detect the headset type and to enable this feature if it's running on a Q3 or Q3S. I'm looking at DeviceInfo, but the only field that seems to indicate the device type is "Name." This is technically changeable by the user so I'd really rather not use it. "Model" returns "Quest" for seemingly all devices, so it's not an option.

Question: what's the easiest way to definitively determine whether the headset has passthrough camera support from a Maui/Xamarin app? Can I load the OpenXR runtime and call into that somehow? I've tried to link it using [DllImport], but it says it can't find the library. I tried to load the library directly but get an error "library is not accessible for the namespace".