Tor works far better for WebGL fingerprinting blocking, but is still compatible with webGL... This extension isn't compatible with Google maps, it's not open source and buggy.

You can disable WebGL fingerprinting WITHOUT BUGS ON GOOGLE MAPS and it works BETTER by applying some settings in about:config :

WebGL 1 anti fingerprint:

webgl.min_capability_mode : True

Then you also want to prevent WebGL 2 fingerprinting:

webgl.enable-webgl2 : false

Finally there's another 3 settings that are disabled on Tor :

webgl.enable-surface-texture : false
webgl.disable-fail-if-major-performance-caveat : True

And the most important : webgl.enable-debug-renderer-info : false

If you DONT want to disable webgl, you can :

1) Install CanvasBlocker and set it to maximum protection
2) Set webgl.enable-debug-renderer-info to false.

Explanation: CanvasBlocker will spoof any webGL fingerprinting (you can try here : https://webbrowsertools.com/webgl-fingerprint/ ID should switch when you restart your browser and red solid box method should be "true", it's normal).
And the 2nd setting prevents websites to know exactly whats your GPU name and driver.

Not working , always Hash of WebGL fingerprint detected and not randomized.

Not particularly useful if I need to disable it in order to use a site that I'm already logged into. If I use Google Maps there's no search bar, but I'm already logged in to Google on my Google container so there's no point in hiding from fingerprinting seeing as they can track me with my active session. There's no way to disable it on a per-site basis or temporarily through a toolbar UI but rather has to be disabled in the Add-On config by scrolling to it, selecting disable from the ellipsis menu.

I'd love to rate it 5-stars except that I'm having to keep it off so it's not of much use to me.