The visibility of the IP address is what I am testing right now. We can always make it go through an internal Tor implementation, which I am also testing right now. But Tor won't work for voice and video calls later. But I think that use case is less sensitive of IP leakage since the user approves the call when receiving it. Lots to do yet.
you could wait till keet.io is open sourced and integrate it
Party A and B share their online-ness through Nostr. They establish a temporary connection through Tor to exchange actually sensitive information. The channel is closed, and a clearnet connection is created - with only the two parties knowing the details (ip, port, perhaps encryption keys) Just a spontaneous thought.
With arti you can configure tor to work fine for video calls on a phone.