I hope one day we get a new embedded FF through Servo or something.
I remember how excited I was back in the old days when I could change KDE's browser Konqueror's engine from KHTML to Gecko in just a setting (or was it a tab?)
Indeed. Scrolling Monaco editor here https://microsoft.github.io/monaco-editor/ feels much smoother on Firefox than on Chrome for me in my very unscientific macOS test.