Firefox has per-site settings for whether the canvas should be accessible which are very useful, but they don't have per-site settings for WebGL, it's either on or off for the entire profile. Which kind of defeats the point of Canvas blocking since (at least last time I checked) WebGL fingerprinting is possible regardless of whether Canvas can be read from.
I'm sure there's some technical reason, but it really seems like turning Canvas reads off for a site should also turn off WebGL.
