Try MaterialFox (https://github.com/muckSponge/MaterialFox https://github.com/muckSponge/MaterialFox). It smooths out many of the rough edges that make Firefox

Try MaterialFox (https://github.com/muckSponge/MaterialFox https://github.com/muckSponge/MaterialFox). It smooths out many of the rough edges that make Firefox feel a bit clunky on macOS.