This is a wonderful paper that includes many optimization tricks that are generally applicable, including various optimizations that they retrofitted into lld. But I thought there was one meta optimization that was especially interesting (from page 2):

> A new linker's early adopters knowingly accept such differences, which is one reason why drastic improvements tend to come from new linkers rather than existing ones

This is true of many things, not just linkers. I think this is encouraging for people to (re)try things that have already been done, because newcomers are allowed to take risks that established things can't take.