Well, as mentioned, I've yet to find something that can replace Maud without sacrificing it's advantages (in-code inheritance, code-sharing and compile-time typ

Well, as mentioned, I've yet to find something that can replace Maud without sacrificing it's advantages (in-code inheritance, code-sharing and compile-time type-safety). So even if it's not the "optimal approach" as you title it, it's the ergonomic approach for me because it doesn't get in my way.