WebKit and Blink have diverged quite substantially at this point and have several large differences. One is that WebKit is more geared toward embedding in appli

WebKit and Blink have diverged quite substantially at this point and have several large differences. One is that WebKit is more geared toward embedding in applications using whatever UI framework and language whereas Blink is more married to Chromium. Firefox configs like you mention are possible only because of custom userchrome, which Mozilla has indicated intent to remove sooner than later.