Search engines now blocked from indexing non-canonical pages

[j127]

@rrit

May we add <a rel="nofollow" …> to all links doing this topic-answer deep-linking? Thereby we might save even more of this precious and limited crawl budget of search engines:
the search engine would neither extract the link in the first place nor do a call to the url. As calling the url results in a response with a X-Robots-Tag: noindex http-header causing the response to be ‘trashed’ by adding the url to the search engines internal ‘noindex’-list.

I agree with the first part of your post, but I don’t think internal nofollow is ideal. Internal links help tell search engines which pages on the site are important. Google isn’t going to follow every link it sees, because it knows that it’s seen them before. If they see a URL like example.com/t/1234/5 but have already crawled it and knows that its canonical URL is example.com/t/1234, they probably aren’t going to waste their computing resources visiting the non-canonical version multiple times.