Current Windows on ARM GPUs don't support
extenral memory. External memory is required
for OpenXR. So most likely OpenXR will not work
on these devices.
Most (read all) OpenXR platforms that support
vulkan also require external memory. So might
just be that those platforms won't work at all
on these devices.
In any case when not supported, the GHOST
OpenXR platform will use CPU for data transfer.