I'm keeping an eye out too. I've seen a few vulnerabilities mentioned already for this tech. This site (https://hacks.mozilla.org/2020/04/experimental-webgpu-in-fir...) suggests that setting the options “dom.webgpu.enabled = true” and “gfx.webrender.all = true” to false (where needed) could prevent it from running. I'm also guessing it's use will depend on javascript which I block by default.