It is possible to advertise your .onion address and offer automatic redirect to it for Tor Browser users using the "Onion-Location" HTTP header. Example with my personal home page:
It would be interesting to try to see if the Tor Browser has a TOFU policy and warn its user if the onion address change after they visited the site once.
If it is the case then you combine the ease of access of typing a normal domain name and the Onion security through an HSTS equivalent mechanism.
Is there some sort of attack possible here where you could hand out unique onion addresses to each visitor, so when they connect with Tor you could fingerprint their Tor connection and match it to their cleartext connection? *takes off his black hat*
If it is the case then you combine the ease of access of typing a normal domain name and the Onion security through an HSTS equivalent mechanism.