I've thought about the Canonical and it could be a massive pain in the arse because of the order that the page is contructed 🙂

Even though all of those URLs work and it's possible to link to them, there'd need to be links to them which Google's reading and indexing. Which makes me feel that it's unlikely the same content would be indexed via multiple URLs. But it's possible. So I should try to overcome my fear and figure out the solution!

Incidentally, I've just written this comment which might be of interest.

It's tricky. I think that if Steemit's users were better at choosing appropriate URLs, option 3 would probably have a stronger proposition.

Let's have a look at 10 random posts from my interface that are in communities and see what tags they use:

1. #club5050
2. #retrogames ✅
3. #diarygame
4. #premoncion
5. #story
6. #thediarygame
7. No Tag - so hive-xxxxxx would be used
8. #photography
9. #steemexclusive
10. #steem

Probably better than I expected but not many that seem particularly good (number 2, 8 and maybe 4).