I wonder if a better way forward is to focus on tools (e.g., a petname system in Tor Browser) to automate dealing with onion addresses rather than making them easier to deal with for humans.
I worked on implementing the X.500 Directory Project which had similar goals for e-mail addresses. That experience convinced me of the need for simplicity and accessibility at all levels, unless you want to port the entire stack to TorPetSpace and watch the code rot.