So #LibreWolf added a feature where instead of blanket banning/allowing WebGL, it should now prompt the user per site to allow it. I say should, as I am not seeing any prompts despite the console log suggesting that it is prompting the user, so I remain unable to make use of WebGL. Running version 148.0.2-3 on #NixOS, if anyone else is facing the same trouble or has solved the issue. The most relevant site to get working for me would be https://hexfriend.net for play-by-post tabletop gaming purposes, as I feel icky with my workaround of nix-shell -p chromium --run chromium.