alt Hacker NewsPSA (for the nth time): about:config is not a supported way of configuring Firefox, so if you tweak features with about:config, don't be surprised if those tweaks stop working without warning.
PSA (for the nth time): about:config is not a supported way of configuring Firefox, so if you tweak features with about:config, don't be surprised if those tweaks stop working without warning.
Mozilla tells you to use it so it so that seems supported enough to me (example: https://support.mozilla.org/en-US/kb/how-stop-firefox-making...)
That said, they're admittedly terrible about keeping their documentation updated, letting users know about added/depreciated settings, and they've even been known to go in and modify settings after you've explicitly changed them from defaults, so the PSA isn't entirely unjustified.