Update for others who are considering using external IPs for name resolution: I did not find a clear answer, but I did come across a post from about a month ago that discusses a very similar issue, but viewed from a security rather than a performance perspective: [tor-relays] Exit relays and DNS privacy - #9 by foreststack_dmc.chat. The thread doesn’t come to a clear conclusion, but the discussion is still very relevant to this topic. At this point, I guess the only way forward is to test it in practice. I’ll report back with the setup used and results.