To me, canonical answers is something live, that grows and improves over time. Yes, we do have canonical Q&A posted with this intention, and we are very happy and grateful to those who posted them! However, I think most of the answers in List of canonical questions are a result of distilling: they were once posted as an answer to a specific topic, then got motion over time by a lot of visitors commenting, upvoting, suggesting modifications... until they became a beautiful thing that is very useful to many.
This is how I like to see the canonical questions. I guess I have some in Stack Overflow: posts with some hundreds of upvotes, hundreds of thousands of visits and quite a lot of edits by different users to polish the post. And this is, in my opinion, the best reward of these answers: to have others improve them, to get some comments showing gratitude (or even emails!), to have it referenced in other sites outside the Stack Exchange network.
I agree the gamification is cool and getting a badge can be nice, but after a while, once you get enough reputation to have all the privileges in the site, I think that getting human reward is way warmer than any badge. For this, I would say: let's show gratitude by improving these answers, keeping them clean, expressing our gratitude to the authors and honouring their effort by linking them whenever it is necessary.