Nesting another answer from the same site letting it be externally updated.

gistfile1.txt

There are several questions about duplicating other user answer or just copying own answer etc...

This new feature would allow us to paste the link in a special way, that would show the other answer contents while having our own considerations above or below it.
When it is updated there, such changes would be shown on the nested contents too.

It could even be cross-site, as long such sites are from the same group (this means it uses the same safe content rules of text and media), and it could store the external site contents in a cache, in case the other site goes offline (like google caches homepages even in simple text).

The idea is, as the external answer won't apply word to word, our considerations would make the nested answer coherent with the current question, in wich case it would not be a duplicate.