As with most proxy/firewall software that customers add to their computers to increase security, we can tell them to add an exception to the whitelist for localhost (127.0.0.1), but in the case of Tor, I just don't know enough about the internals of how it goes about blocking things it deems potentially harmful to know whether adding an exception for 127.0.0.1 would be considered voiding the protection offered by Tor. The Tor proxy itself is contained on 127.0.0.1, port 9051, so bypassing for localhost might inadvertently induce a whole host of other, non-1Password applications/utilities/helper programs to pass information outside of the Tor channels, potentially exposing your real IP address. I just don't know. In my own testing just now, i can confirm that adding 127.0.0.1 to Tor's Preferences => Advanced => Network Settings does indeed allow the 1Password extension to work...but at what cost to the anonymity afforded by Tor, I have no idea.