You could simply add "index" to the page when accessed with /seo/url and noindex when accessed with the cryptic url. Additionally you can enforce that using .htaccess or nginx rules also. Your Framework and HTTP-Router class just has to support multiple URLs per page.
Basically your CMS or Framework must allow to have multiple routes like site.com/best/watch/casio and site.com/→@ðŋ]æ~@¢“«¢“¹²³»«@€^ linking to the same page.
I've used that in the past to switch languages dependant on url-path + browser-language. /en/my-article would show that english article to a german visitor, but everything else on the site like nav, terms etc. would be German. To access the Enlish site, the german visitor would have to click the appropriate flag. I could have easily added the feature to read that same article in German, by a click on a flag in the bread-crumb's mini drop-down. Example: blog»my-article[v] a click on [v] would open blog»mein-artikel etc.
Basically your CMS or Framework must allow to have multiple routes like site.com/best/watch/casio and site.com/→@ðŋ]æ~@¢“«¢“¹²³»«@€^ linking to the same page.
I've used that in the past to switch languages dependant on url-path + browser-language. /en/my-article would show that english article to a german visitor, but everything else on the site like nav, terms etc. would be German. To access the Enlish site, the german visitor would have to click the appropriate flag. I could have easily added the feature to read that same article in German, by a click on a flag in the bread-crumb's mini drop-down. Example: blog»my-article[v] a click on [v] would open blog»mein-artikel etc.