From w3ctag/design-reviews#626 (comment)

Should there be a higher granularity for selecting devices? For example, for cases where one wants to select a high-VRAM device (e.g. for machine learning workloads) or the non-dominant (e.g. secondary device which hopefully will not jank the current compositor) device. Allowing a single application to be the dominant resource user is not new, but it is definitely something that want to be careful about.